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Table of Contents

Connection Commands

Connection Commands

This chapter describes the commands used to make connections from a router to terminals or network devices.

For connection tasks and examples, refer to the "Making Connections to Network Devices" chapter in the Access Services Configuration Guide.

clear tcp

To clear a TCP connection, use the clear tcp privileged EXEC command.

clear tcp {line line-number | local host-name port remote host-name port | tcb address}
Syntax Description
line line-number TTY line number of the TCP connection to clear.
local host-name port
remote host-name port
Local router's host name and port and remote router's host name and port of the TCP connection to clear.
tcb address Transmission Control Block (TCB) address of the TCP connection to clear. The TCB address is an internal identifier for the end point.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

The clear tcp command is particularly useful for clearing hung TCP connections.

The clear tcp line line-number command terminates the TCP connection on the specified TTY line. Additionally, all TCP sessions initiated from that TTY line are terminated.

The clear tcp local host-name port remote host-name port command terminates the specific TCP connection identified by the host name/port pair of the local and remote router.

The clear tcp tcb address command terminates the specific TCP connection identified by the TCB address.

Examples

The following example clears a TCP connection using its TTY line number. The show tcp command displays the line number (tty2) that is used in the clear tcp command.

Router# show tcp
 
    tty2, virtual tty from host router20.cisco.com
    Connection state is ESTAB, I/O status: 1, unread input bytes: 0
    Local host: 171.69.233.7, Local port: 23
    Foreign host: 171.69.61.75, Foreign port: 1058
 
    Enqueued packets for retransmit: 0, input: 0, saved: 0
 
    Event Timers (current time is 0x36144):
    Timer          Starts    Wakeups            Next
    Retrans             4          0             0x0
    TimeWait            0          0             0x0
    AckHold             7          4             0x0
    SendWnd             0          0             0x0
    KeepAlive           0          0             0x0
    GiveUp              0          0             0x0
    PmtuAger            0          0             0x0
 
    iss: 4151109680  snduna: 4151109752  sndnxt: 4151109752     sndwnd:  24576
    irs: 1249472001  rcvnxt: 1249472032  rcvwnd:       4258  delrcvwnd:     30
 
    SRTT: 710 ms, RTTO: 4442 ms, RTV: 1511 ms, KRTT: 0 ms
    minRTT: 0 ms, maxRTT: 300 ms, ACK hold: 300 ms
 
Router# clear tcp line 2
    [confirm]
     [OK]

The following example clears a TCP connection by specifying its local router host name and port and its remote router host name and port. The show tcp brief command displays the local (Local Address) and remote (Foreign Address) host names and ports to use in the clear tcp command.

Router# show tcp brief
    TCB       Local Address           Foreign Address        (state)
    60A34E9C  router1.cisco.com.23      router20.cisco.1055  ESTAB
 
Router# clear tcp local router1 23 remote router20 1055
    [confirm]
     [OK]

The following example clears a TCP connection using its TCB address. The show tcp brief command displays the TCB address to use in the clear tcp command.

Router# show tcp brief
    TCB       Local Address           Foreign Address        (state)
    60B75E48  router1.cisco.com.23      router20.cisco.1054  ESTAB
 
Router# clear tcp tcb 60B75E48
    [confirm]
     [OK]
Related Commands

show tcp
show tcp brief

connect

To log on to a host that supports Telnet, Rlogin, or LAT, use the connect EXEC command.

connect host [port] [keyword]
Syntax Description
host A host name or an IP address.
port (Optional) A decimal TCP port number; the default is the Telnet router port (decimal 23) on the host.
keyword (Optional) One of the options listed in Table 18.


Table 18: Telnet Connection Options
Option Description
/debug Enables Telnet debugging mode.
/line Enables Telnet line mode. In this mode, the Cisco IOS software sends no data to the host until you press Return. You can edit the line using the standard Cisco IOS software command editing characters. The /line keyword is a local switch; the remote router is not notified of the mode change.
/noecho Causes the connection to start in a mode where it does NOT echo characters typed by the user (the telnet spec defines local echoing as the default, this changes the default to NO local echoing). This does not prevent the remote site from doing echoing, and does not prevent local echoing from being negotiated at a later time. It is primarilly used when talking to systems that do not correctly implement a telnet server.
/route path Specifies loose source routing. The path argument is a list of host names or IP addresses that specify network nodes and ends with the final destination.
/source-interface Causes the ip source address used by the router for the tcp connection to be taken from the interface specified. See also "ip telnet source-interface" config command.
/stream Turns on stream processing, which enables a raw TCP stream with no Telnet control sequences. A stream connection does not process Telnet options and can be appropriate for connections to ports running UUCP and other non-Telnet protocols.
port-number Port number.
bgp Border Gateway Protocol.
chargen Character generator.
cmd rcmd Remote commands.
daytime Daytime.
discard Discard.
domain Domain Naming Service.
echo Echo.
exec EXEC.
finger Finger.
ftp File Transfer Protocol.
ftp-data FTP data connections (used infrequently).
gopher Gopher.
hostname Network Information Center (NIC) hostname server.
ident Ident Protocol.
irc Internet Relay Chat.
klogin Kerberos login.
kshell Kerberos shell.
login Login (rlogin).
lpd Printer service.
nntp Network News Transport Protocol.
node Connect to a specific LAT node.
pop2 Post Office Protocol v2.
pop3 Post Office Protocol v3.
port Destination LAT port name.
smtp Simple Mail Transport Protocol.
sunrpc Sun Remote Procedure Call.
syslog Syslog.
tacacs Specify TACACS security.
talk Talk.
telnet Telnet.
time Time.
uucp Unix-to-Unix Copy Program.
whois Nickname.
www World Wide Web (HTTP).
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

With the Cisco IOS software implementation of TCP/IP, you are not required to enter the connect, telnet, lat, or rlogin commands to establish a terminal connection. You can just enter the learned host name--as long as the host name is different from a command word in the Cisco IOS software.

To display a list of the available hosts, enter the following command:

show hosts

To display the status of all TCP connections, enter the following command:

show tcp

The Cisco IOS software assigns a logical name to each connection, and several commands use these names to identify connections. The logical name is the same as the host name, unless that name is already in use, or you change the connection name with the EXEC command name-connection. If the name is already in use, the Cisco IOS software assigns a null name to the connection.

Examples

The following example routes packets from the source system host1 to kl.sri.com, then to 10.1.0.11, and finally back to host1:

Router> connect host1 /route:kl.sri.com 10.1.0.11 host1
 

The following example connects to a host with logical name host1:

Router> host1
Related Commands

lat
telnet

disconnect

To disconnect a line, use the disconnect EXEC command.

disconnect [connection]
Syntax Description
connection (Optional) Number of the line or name of the active network connection to be disconnected.
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Do not disconnect a line to end a session. Instead, log off the host, so that the Cisco IOS software can clear the connection. Then end the session. If you cannot log out of an active session, disconnect the line.

Example

In the following example, the user disconnects from the device Slab to return back to the router.

Slab% disconnect
  Connection closed by remote host
Router#
Related Command

login (EXEC)

lat

To connect to a LAT host, use the lat EXEC command.

lat name [node nodename | port portname | /debug]
Syntax Description
name LAT-learned service name.
node nodename (Optional) Specifies a connection to a particular LAT node that offers a service. If you do not include the node name option, the node with the highest rating offering the service is used. Use the show lat nodes EXEC command to display information about all known LAT nodes.
port portname (Optional) Specifies a destination LAT port name. This keyword is ignored in most time-sharing systems, but is used by routers and network access servers offering reverse LAT services. Reverse LAT involves connecting to one router from another, so that the target router runs the host portion of the protocol. Enter the port name in the format of the remote system as the portname argument.
/debug (Optional) Enables a switch to display parameter changes and other special messages.
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

After entering the lat command, you can quit the connection by pressing Ctrl-C, or complete the connection by entering the password for a given service.

You can have several concurrent LAT sessions open and switch back and forth between them. To open a subsequent session, first enter the escape sequence (Ctrl-Shift-6 then x [Ctrl^x] by default) to suspend the current session. Then open a new session.

To list the available LAT services, use the show lat services EXEC command.

You can temporarily define the list of services to which you or another user can connect. To do so, use the terminal lat out-group command to define the group code lists used for connections from specific lines.

To exit a session, simply log off the remote system. Then, terminate an active LAT session by entering exit.

If your preferred transport is set to lat, you can use the connect command in place of the lat command. Refer to the Access Services Configuration Guide for more information about configuring a preferred transport type. When your preferred transport is set to none or to another protocol, you must use the lat command to connect to a LAT host.

Examples

The following example establishes a LAT connection from the router named Router_A to host eng2:

Router_A> lat eng2
Trying ENG2...Open
         ENG2 - VAX/VMS V5.2
Username: JSmith
Password:
    Welcome to VAX/VMS version V5.2 on node ENG2
    Last interactive login on Friday,  1-APR-1994 19:46

The system informs you of its progress by displaying the messages "Trying <system>..." and then "Open." If the connection attempt is not successful, you receive a failure message.

The following example establishes a LAT connection from the router named Router_B to something named our-modems and specifies port 24, which is a special modem:

Router_B> lat our-modems port 24

The following example establishes a LAT connection from the router named Router_C to something named our-modems and specifies a node named eng:

Router_C> lat our-modems node eng

The following example uses the LAT session debugging capability:

Router_D> lat Eng2 /debug
Trying ENG2...Open
        ENG2 - VAX/VMS V5.2
 Username: JSmith
 Password:
    Welcome to VAX/VMS version V5.2 on node ENG2
    Last interactive login on Tuesday, 5-APR-1994 19:02
[Set Flow out off, Flow in on, Format 8:none, Speed 9600/9600]
[Set Flow out off, Flow in on, Format 8:none, Speed 9600/9600]
$ set ter/speed=2400
[Set Flow out off, Flow in on, Format 8:none, Speed 2400/2400]

A variety of LAT events are reported, including all requests by the remote system to set local line parameters. The messages within brackets ([ ]) are the messages produced by the remote system setting line characteristics to operating system defaults.

Related Commands

connect
show lat services
terminal lat

lock

To set up a temporary password on a line, use the lock EXEC command.

lock
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

You can prevent access to your session while keeping your connection open by setting up a temporary password. To lock access to the terminal, follow this procedure:

Step 1 Issue the lock command.

When you issue this command, the system prompts you for a password.


Step 2 Enter a password, which can be any arbitrary string.

The screen clears and displays the message "Locked."


Step 3 To regain access to your sessions, re-enter the password.

The Cisco IOS software honors session timeouts on a locked lines. You must clear the line to remove this feature. The system administrator must set the line up to allow use of the temporary locking feature by using the lockable line configuration command.

Example

The following command locks access to the terminal line to which the user is connected. Only this user can access the session:

Router(config-line)# lockable
Router(config-line)# Ctrl-z
Router# copy running-config startup-config
Building configuration...
OK
Router# lock 
Password: 
Again:
                       Locked
Password:
Router#
Related Commands

A dagger (+) indicates that the command is documented in the "Terminal Lines and Modem Support Commands" chapter.

lockable +
login (EXEC)

login (EXEC)

To change a login username, use the login EXEC command.

login
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

You can change a login username if you must match outgoing access list requirements or other login prompt requirements.

When you enter this command, the Cisco IOS software prompts you for a username and password. Enter the new username and the original password. If the username does not match, but the password does, the Cisco IOS software updates the session to the new username with which the login command attempt was made.

If no username and password prompts appear when you enter this command, the network administrator did not specify that a username and password be required at login time. If both the username and password are entered correctly, the session becomes associated with the specified username.

When you access a system using TACACS security with this command, you can enter your login name or specify a TACACS server by using the following command when the "Username:" prompt appears:

user @tacacs-server

The TACACS server must be one of those defined in a Cisco IOS software configuration file. For more information, refer to the "Specify a TACACS Host" section in the Security Configuration Guide, or refer to the tacacs-server host command in the Security Command Reference book.

If you do not specify a host, the Cisco IOS software tries each of the TACACS servers in the list until it receives a response.

If you do specify a host that does not respond, no other TACACS server is queried. The Cisco IOS software will deny access or function according to the action specified by the tacacs-server last-resort command, if one is configured.

If you specified a TACACS server host with the user @tacacs-server argument, the TACACS server specified will be used for all subsequent authentication or notification queries, with the possible exception of SLIP address queries.

Example

The following example shows how login usernames and passwords can be changed. In this example, a user currently logged on under the username user1 attempts to change that login name to user2. After entering the login command, the user enters the new username, but enters an incorrect password. Because the password does not match the original password, the system rejects the attempt to change the username.

Router> login
Username: user2
Password:
% Access denied
Still logged in as "user1"

Next, the user attempts the login change again, with the user name user2, but enters the correct (original) password. This time the password matches the current login information, the login username is changed to user2, and the user is allowed access to the EXEC at the user-level.

Router> login
Username: user2
Password:
Router>
Related Commands

A dagger (+) indicates that the command is documented in the "Terminal Lines and Modem Support Commands" chapter.

lock
lockable
+

name-connection

To assign a logical name to a connection, use the name-connection user EXEC command.

name-connection
Default

None

Command Mode

User EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

This command can be useful for keeping track of multiple connections.

You are prompted for the connection number and name to assign. The where command displays a list of the assigned logical connection names.

Example

The following example assigns the logical name host1 to the connection:

Router> name-connection host1
Related Command

where

pad

To log on to a PAD, use the pad user EXEC command.

pad {X.121-address | hostname} [/cud text] [/debug] [/profile name] [/reverse]
Syntax Description
X.121-address Specifies the X.121 address of the X.25 host.
hostname Specifies the X.25 host name if the host-to-address mapping has been set with the X.25 host command.
/cud text (Optional) Includes the specified text in the Call User Data field of the outgoing Call Request Packet.
/debug (Optional) Displays the informational level of logging messages whenever the remote host changes an X.3 parameter setting, or sends any other X.29 control packet.
/profile name (Optional) Sets X.3 PAD parameters for the name script. Same as issuing the x29 profile global configuration command when
translating X.25.
/reverse (Optional) Causes reverse-charge calls to be accepted on a per-call (rather than a per-interface) basis.
Default

None

Command Mode

User EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

The pad command supports one-word connections. You do not have to enter the pad command; just entering the address is enough to start connection.

You can have several PAD connections open at the same time and switch between them. You also can exit a connection and return to the user EXEC prompt at any point. To open a new connection, first exit the current connection by entering the escape sequence (Ctrl-Shift-6 then x [Ctrl^x] by default) to return to the EXEC prompt, then open the new connection.

To display information about packet transmission and X.3 PAD parameter settings, enter the show x25 pad command.

To exit a session, simply log off the remote system. Then, terminate an active session by entering the exit command.

Example

The following example starts a PAD session:

Router> pad 123456789
Trying 123456789...Open
Router>
Related Command

A dagger (+) indicates that the command is documented in the "Protocol Translation Commands" chapter.

translate x25 +

ppp

To start an asynchronous connection using PPP, use the ppp EXEC command.

ppp {/default | {remote-ip-address | remote-name} [@tacacs-server]} [/routing]
Syntax Description
/default (Optional) Makes a PPP connection when a default address has been configured.
remote-ip-address IP address of the client workstation or PC. This parameter can only be specified if the line is set for dynamic addresses using the async address dynamic line configuration command.
remote-name Name of the client workstation or PC. This parameter can be specified if the line is set for dynamic addresses using the async address dynamic line configuration command.
@tacacs-server (Optional) IP address or IP host name of the TACACS server to which the user's TACACS authentication request is sent.
/routing (Optional) Indicates that the remote system is a router and that routing messages should be exchanged over the link. The line must be configured for asynchronous routing using PPP encapsulation.
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

When you connect from a remote node computer to an EXEC session on the access server and want to connect from the access server to a device on the network, issue the ppp command.

If you specify an address for the TACACS server (either /default or tacacs-server), the address must be the first parameter in the command after you type ppp. If you do not specify an address or enter default, you are prompted for an IP address or host name. You can enter default at this point.

To terminate a session, disconnect from the device on the network using the command specific to that device. Then, exit from the EXEC by using the exit command.

Example

The following example shows a line that is in asynchronous mode using PPP encapsulation (see Figure 3). The PC's name is ntpc--assuming that the name ntpc is in the Domain Naming System (DNS) so that it can be resolved to a real IP address). The PC must be running a terminal emulator program.

Router> ppp ntpc@server1

Figure 3: Using the PPP EXEC Command


resume (setting X.3 PAD parameters)

To set X.3 parameters, use the resume EXEC command as follows:

resume [connection] [/set parameter:value]
Syntax Description
connection (Optional) The name or number of the connection; the default is the most recent connection.
/set parameter:value (Optional) Sets the X.3 connection options and PAD parameters for the Cisco IOS software. Refer to Table 19 for PAD parameters.

Refer to the "X.3 PAD Connections" section in the "Making Network Connections" chapter of the Access Services Configuration Guide for a list of these connection options.


Table 19: PAD Parameters
Parameter Action Value Description
1 Escape from Data Transfer Not supported.
2 Local Echo Mode

0

1

No local echo (incoming PAD connection default).

Local echo on (outgoing connection default).

3 Data Forward Character

0

1

2

4

8

16

32

64

None--full packet.

Forward packet on receipt of an alphanumeric character.

Forward packet on receipt of a RETURN (outgoing connection default).

Forward packet on receipt of ESCAPE, BEL, ENQ, or ACK.

Forward packet on receipt of DEL, CAN, or DC2.

Forward packet on receipt of ETX or EOT.

Forward packet on receipt of HT, LT, VT, or FF.

All other characters in the ASCII chart.

4 Idle Timer 0

1-255

No timer.

Delay value in twentieths of a second (default for both connection types is 1).

5 Device Control Not supported.
6 PAD Service Signals Not supported.
7 Receipt of Break 0

1

2

4

8

16

21

Ignore the Break signal.

Transmit an INTERRUPT packet to notify the remote host or another PAD that the Break signal was generated.

Transmit a RESET packet to reset the virtual circuit.

Transmit an X.29 break indication to the remote host, or to a PAD (outgoing connection default).

Escape from data transfer mode.

Discard output to the terminal by setting parameter 8 to a value of 1.

Combination of values 1, 4, and 16 (incoming connection default).

8 Discard Output 0

1

Normal data delivery to the terminal (outgoing connection default).

Discard all output to the terminal; set by parameter 7.

9 Return Padding Not supported.
10 Line Folding Not supported.
11 Baud Rate 10

5

9

0

1

6

8

2

4

3

7

11

12

13

14

15

16

17

18

50 baud.

75 baud.

100 baud.

110 baud.

134.5 baud.

150 baud.

200 baud.

300 baud.

6001 baud.

1200 baud.

1800 baud.

75/12002 baud.

2400 baud.

4800 baud.

9600 baud.

19200 baud.

48000 baud.

56000 baud.

64000 baud.

12 Input Flow Control Not supported.
13 Line Feed Insertion 0

1

2

4

Do not insert (outgoing connection default).

Insert after transmitting RETURN to the terminal.

Insert after echoing RETURN to the terminal.

Insert after echoing RETURN to the remote host.

14 Line Feed Padding Not supported.
15 Local Editing 0

1

Disables editing capabilities.

Enables editing capabilities.

16 Character Delete 0-127 Select one ASCII character. Default is ASCII 127 (Del).
17 Line Delete 0-127 Select one ASCII character. Default is ASCII 21
(Ctrl-U).
18 Line Display 0-127 Select one ASCII character. Default is ASCII 18
(Ctrl-R).

1 600 is the beginning of values that are PAD-type dependent.
2 75 is from PAD; 1200 is to PAD.
Default

For outgoing connections, the X.3 parameters default to the following:

2:1, 3:2, 4:1, 7:4, 16:127, 17:21, 18:19

All other parameters default to zero, but can be changed using the /set switch option with either the resume command or the x3 command.

For incoming PAD connections, the software sends an X.29 SET PARAMETER packet to set only the following parameters:

2:0, 4:1, 7:21, 15:0
Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

The resume [connection] command first appeared in Cisco IOS Release 9.1.

The /set switch sets the X.3 parameters defined by parameter number and value, separated by a colon. You set one or more X.3 PAD parameters, as follows:

Step 1 Escape out of the current session by pressing the escape sequence (Ctrl-Shift-6 then x [Ctrl^x] by default) and return to the EXEC prompt.

Step 2 Issue the where command, to list the open sessions. All open sessions associated with the current terminal line are displayed.

Step 3 Enter the resume command, followed by the parameter, a colon, and then the value to be set.

Example

The following example specifies that local echo mode be turned on for a connection to the device Swift (which is session number 3). As shown in Table 19, "local echo on" uses the parameter 2 and the value 1 (represented as 2:1 in this example):

Swift% ^^X 
Router> resume 3 /set 2:1
Swift% 

resume (switching sessions)

To switch to another open Telnet, rlogin, LAT, or PAD session, use the resume EXEC command.

resume [connection] [keyword]
Syntax Description
connection (Optional) The name or number of the connection; the default is the most recent connection.
keyword (Optional) One of the options listed in Table 20.
/set parameter:value (Optional) Sets PAD parameters for the Cisco IOS software (see Table 19).


Table 20: Telnet and rlogin Resume Options
Option Description
/debug Displays parameter changes and messages. In the Cisco IOS software, this option displays informational messages whenever the remote host changes an X.3 parameter, or sends an X.29 control packet.
/echo Performs local echo.
/line Enables line-mode editing.
/nodebug Cancels printing of parameter changes and messages.
/noecho Disables local echo.
/noline1 Disables line mode and enables character-at-a-time mode, which is the default.
/nostream Disables stream processing.
/set parameter:value Sets X.3 connection options. Refer to the "X.3 PAD Connections" section in the "Making Network Connections" chapter of the Access Services Configuration Guide for a list of these connection options.
/stream Enables stream processing.

1 /noline is the default keyword.
Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

You can have several concurrent sessions open and switch back and forth between them. The number of sessions that can be open is defined by the session-limit command, which is described in the "Configuring Terminal Lines and Modem Support" chapter of the Access Services Configuration Guide and the "Terminal Lines and Modem Support Commands" chapter of this publication.

You can switch between sessions by escaping one session and resuming a previously opened session, as follows:

Step 1 Escape out of the current session by pressing the escape sequence (Ctrl-Shift-6 then x [Ctrl^x] by default) and return to the EXEC prompt.

Step 2 Issue the where command, to list the open sessions. All open sessions associated with the current terminal line are displayed.

Step 3 Enter the resume command and the session number to make the connection.

You also can resume the previous session by pressing the Return key.


The Ctrl^x, where, and resume commands are available with all supported connection protocols.

Examples

The following example shows how to escape out of a connection and to resume connection 2:

Swift% ^^X 
Router> resume 2 

You can omit the command name and simply enter the connection number to resume that connection. The following example illustrates how to resume connection 3:

Router> 3 
Related Commands

show sessions
where

rlogin

To log onto a UNIX host using rlogin, use the rlogin EXEC command.

rlogin host [debug] [/user username]
Syntax Description
host Specifies the host name or IP address.
debug (Optional) Enables debugging output from the rlogin protocol.
/user username (Optional) Specifies a remote username. The rlogin protocol will not present you with the "login:" prompt.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You can have several concurrent rlogin connections open and switch back and forth between them. To open a new connection, suspend the current connection by pressing the escape sequence (Ctrl-Shift-6 then x [Ctrl^x] by default) to return to the EXEC prompt, then open a new connection. A user cannot automatically log on to a UNIX system from the router, but must provide a user ID and a password for each connection.

If your preferred transport is set to rlogin, you can use the connect command in place of the rlogin command. Refer to the Access Services Configuration Guide for more information about configuring a preferred transport type. When your preferred transport is set to none or to another protocol, you must use the rlogin command to connect to a host.

To terminate an active rlogin session, issue the appropriate command from the following list at the UNIX prompt of the device to which you are connecting:

close
disconnect
exit
logout

quit

Example

The following example makes an rlogin connection to a host at address 108.33.21.2 and enables the message mode for debugging:

Router> rlogin 108.33.21.2 debug
Related Commands

connect
telnet

rlogin trusted-remoteuser-source local

To configure the router to use the current user's name (as discovered during IOS authentication on the router) as the rlogin username on the remote host, use the rlogin trusted-remoteuser-source local global configuration command. Use the no form of this command to restore the default rlogin behavior of prompting the user for the remote username.

rlogin trusted-remoteuser-source local
no rlogin trusted-remoteuser-source local

Syntax Description

This command has no additional options.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1

The current username is only used if the rlogin host /user username command is not enabled. If the current username is not known, rlogin falls back to providing the"login:" prompt to discover a remote username.

Configuring the remote host to consider the Cisco router a "trusted" host should be considered a security hole.

Examples

After you issue the rlogin trusted-remoteuser-source local command, you will not be prompted for a username. The first response you see is the password prompt from the remote system. For example, when this command is not enabled, you must enter your username twice (once at initial system login and once for the rlogin command).

User Access Verification
Username: gmcmilla
Password: 
router> rlogin puli
Trying puli.cisco.com (170.69.3.154)... Open
login: gmcmilla
Password:
Login incorrect

After you issue the rlogin trusted-remoteuser-source local command, you no longer have to specify the username after the rlogin command. The username is automatically copied from the router's user ID.

router> enable
Password: 
router# configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
router(config)# rlogin trusted-remoteuser-source local 
router(config)# ^Z
router# rlogin puli
Trying puli.cisco.com (170.69.3.154)... Open
Password:
Login incorrect

The following example uses the /user root option as an override.

router# rlogin puli /user root
Trying puli.cisco.com (170.69.3.154)... Open
Password:
Login incorrect
login: 
Related Commands

You can use the master indexes or search online to find documentation of related commands.

connect
telnet

send

To send messages to one or all terminal lines, use the send EXEC command.

send {line-number | * | aux number | console number | tty number | vty number}
Syntax Description
line-number Line number to which the message will be sent.
* Sends a message to all TTY lines.
aux number Sends a message to the AUX port.
console number Sends a message to the console port.
tty number Sends a message to an asynchronous line.
vty number Sends a message to a VTY line.
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

The system prompts for the message, which can be up to 500 characters long. Enter Ctrl-Z to end the message. Enter Ctrl-C to abort this command.

Example

The following example sends a message to line number 21:

2509# send *
Enter message, end with CTRL/Z; abort with CTRL/C:
The system 2509 will be shut down in 10 minutes for repairs.^Z
Send message? [confirm]
2509#
***
***
*** Message from tty0 to all terminals:
***
The system 2509 will be shut down in 10 minutes for repairs.
2509#

show entry

To display the list of queued host-initiated connections to a router, use the show entry user EXEC command.

show entry
Command Mode

User EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

You can use this command to determine which LAT hosts have queue entries for printers on routers.

Sample Display

The following is sample output from the show entry command:

sloth# show entry
1 waiting 0:02:22 for port 5 from LAT node BLUE
2 waiting 0:00:32 for port 5 from LAT node STELLA

The display shows that two LAT connections are waiting for access to port 5. The list is ordered so that the lower-numbered entry (which has waited longer) gets to use the line next. The display shows how long each connection attempt has been waiting, for which port, and the user's name.

Table 21 describes the fields in the first line of output shown in the display.


Table 21: Show Entry Field Descriptions
Field Description
1 Number assigned to the queued connection attempt.
waiting 0:02:22 Interval (hours:minutes:seconds) the connection attempt has been waiting.
for port 5 Port for which the connection attempt is waiting.
from LAT node BLUE Name of the user attempting to make the connection.

show hosts

To display the default domain name, the style of name lookup service, a list of name server hosts, and the cached list of host names and addresses on the network to which you can connect, use the show hosts user EXEC command.

show hosts
Command Mode

User EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Sample Display

The following is a sample display from the show hosts output:

sloth# show hosts 
Default domain is CISCO.COM
Name/address lookup uses domain service
Name servers are 255.255.255.255
Host	              Flags       	Age	   Type	       Address(es)
SLAG.CISCO.COM	    (temp, OK)  	1     	IP         	131.108.4.10
CHAR.CISCO.COM    	(temp, OK)  	8     	IP	         192.31.7.50
CHAOS.CISCO.COM	   (temp, OK)  	8     	IP         	131.108.1.115
DIRT.CISCO.COM	    (temp, EX)  	8     	IP         	131.108.1.111
DUSTBIN.CISCO.COM	 (temp, EX)  	0     	IP         	131.108.1.27
DREGS.CISCO.COM	   (temp, EX)  	24    	IP         	131.108.1.30

Table 22 describes significant fields shown in the display.


Table 22: Show Hosts Field Descriptions
Field Description
Host Name of server host.
Flags A temporary entry is entered by a name server; the server removes the entry after 72 hours of inactivity.

A permanent entry is entered by a configuration command and is not timed out. Entries marked "OK" are believed to be valid. Entries marked "??" are considered suspect and subject to revalidation. Entries marked "EX" are expired.

Age Indicates the number of hours since the Cisco IOS software last referred to the cache entry.
Type Identifies the type of address (for example, IP, CLNS, or X.121). If you used the ip hp-host global configuration command, the show hosts command displays these host names as type HP-IP.
Address(es) Shows the address of the host. One host can have up to eight addresses.

show lat services

To display information about learned LAT services in the Cisco IOS software, use the show lat services user EXEC command.

show lat services [service-name]
Syntax Description
service-name (Optional) Name of a specific LAT service.
Command Mode

User EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Sample Display

The following is sample output from the show lat services command:

Router# show lat services
Service Name     Rating   Interface  Node (Address)
ABCDEFGHIJ            5   Ethernet0  CONFUSED (0000.0c00.391f)
GLAD                 84   Ethernet0  BLUE (aa00.0400.9205)
  Ident: Welcome to Big Blue Gateway
WHEEL                83   Ethernet0  WHEEL (aa00.0400.9005)
ZXYW                  5   Ethernet0  CONFUSED (0000.0c00.391f) 

Table 23 describes significant fields shown in this display.


Table 23: Show LAT Services Field Descriptions
Field Description
Service Name LAT service name.
Rating Rating of the service. If a single service is provided by more than one host, the Cisco IOS software connects to the one with the highest rating.
Interface Interface type.
Node Connection address.
(Address) Advertised identification for the service.
Related Commands

show lat sessions
show service

show lat sessions

To display active LAT sessions, use the show lat sessions user EXEC command.

show lat sessions [line-number]
Syntax Description
line-number (Optional) Shows an active LAT session on a specific line.
Command Mode

User EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Sample Display

The following is sample output from the show lat sessions command. In this example, information about all active LAT sessions is displayed. The output is divided into three sections for each session (in this case two sessions): TTY data, session data, and remote node data.

Router> show lat sessions 
tty0, connection 1 to service TERM1
TTY data:
  Name "0", Local usage 1/0, Remote usage disabled
  Flags: Local Connects, Enabled
  Type flags: none
  Config flags: -FlowOut, -FlowIn, Parameter Info
  Flow control ^S/^Q in ^S/^Q out,  Mode Normal, Parity None, databits 8
  Groups:   0
Session data:
  Name TERM1, Remote Id 1, Local Id 1
  Remote credits 2, Local credits 0, Advertised Credits 2
  Flags: none
  Max Data Slot 255, Max Attn Slot 255, Stop Reason 0
Remote Node data:
Node "TERM1", Address 0000.0C00.291F, usage 1
  Timer 59,  sequence 5,  changes 159,  flags 0x0, protocol 5.1
  Recv 56/22/83,  Xmit 41/23/14,  0 Dups, 0 ReXmit
  Groups:   0
tty10, connection 1 to service ENG2
TTY data:
  Name "10", Local usage 1/0, Remote usage disabled
  Flags: Local Connects, Enabled
  Type flags: none
  Config flags: -FlowOut, +FlowIn, Set Parameters, 0x40000000
  Flow control ^S/^Q in ^S/^Q out,  Mode Normal, Parity None, databits 8
  Groups:   0
Session data:
  Name ENG2, Remote Id 1, Local Id 1
  Remote credits 1, Local credits 0, Advertised Credits 2
  Flags: none
  Max Data Slot 255, Max Attn Slot 255, Stop Reason 0
Remote Node data:
Node "ENG2", Address AA00.0400.34DC, usage 1
  Timer 179,  sequence 60,  changes 255,  flags 0x0, protocol 5.1
  Recv 58/29/186,  Xmit 50/36/21,  0 Dups, 0 ReXmit
  Groups:   0 

The following sample output displays information about active LAT sessions on one line, line 10. The output is divided into three sections: TTY data, session data, and remote node data.

Router# show lat sessions 10 
tty10, connection 1 to service ENG2
TTY data:
  Name "10", Local usage 1/0, Remote usage disabled
  Flags: Local Connects, Enabled
  Type flags: none
  Config flags: -FlowOut, +FlowIn, Set Parameters, 0x40000000
  Flow control ^S/^Q in ^S/^Q out,  Mode Normal, Parity None, databits 8
  Groups:   0
Session data:
  Name ENG2, Remote Id 1, Local Id 1
  Remote credits 1, Local credits 0, Advertised Credits 2
  Flags: none
  Max Data Slot 255, Max Attn Slot 255, Stop Reason 0
Remote Node data:
Node "ENG2", Address AA00.0400.34DC, usage 1
  Timer 189,  sequence 61,  changes 247,  flags 0x0, protocol 5.1
  Recv 60/29/186,  Xmit 52/36/21,  0 Dups, 0 ReXmit
  Groups:   0

Table 24 describes the screen output for the preceding two examples.


Table 24: Show LAT Sessions Status Display Field Descriptions
Field Description
TTY data Summary of the LAT-oriented terminal-line-specific data.
Name Name used for this port as a port identification string. The name is reported to remote systems, which can display it in some operating-system dependent manner. This value is also used for targets of host-initiated connections. Currently, this value is hard-wired to be the line number of the associated terminal line.
Local/Remote usage Current status of the terminal. The number is reported as current/maximum, where current is the current number of sessions of a given type, and maximum is the maximum number of sessions allowed (or zero if there is no maximum). If a terminal is being used for outgoing sessions, the local usage is equal to the number of current LAT sessions. If the terminal is being used for incoming sessions, local usage is disabled, and the remote count and maximum is one.
Flags Current state of the line, and whether there are any queued host-initiated connections.
Type flags Report flags not used in the current software release.
Config flags Current port state as reflected by the most recent configuration message exchange.
Flow control Lists set flow control characters.
Groups Group code list currently in use for the line.
Session data Reports various parameters about the connection.
Name For the outbound connection, the name of the remote service to which it is connected. For inbound connections, this field is currently unused.
Remote/Local ID Slot IDs being used to uniquely identify the session multiplexed over the underlying LAT virtual circuit.
Remote/Local/
Advertised Credits
Number of flow control credits that the Cisco IOS software will be sending to the host as soon as possible. The advertised credits are the number of credits that have already been sent.
Flags Transient conditions in the LAT-state machine dealing with the current connection status.
Max Data Slot Maximum number of characters that can be sent in a single data slot.
Max Attn Slot Maximum amount of data that can be sent in an attention message. Current LAT implementations only sends 1-byte attention messages (attention messages are used to flush buffered output). A nonzero value means that remote data flushing can be used; a zero means that it cannot.
Stop Reason Reason the session was stopped, if it was stopped but not deleted. This value is usually zero, indicating that the session has not yet been stopped. If a session persists for a long time with a nonzero stop reason, there is probably a problem in the local LAT software.
Remote Node data Reports information about the remote node. The data includes the same fields as those from the show lat nodes output.
Node Node name as reported by the host computer.
Address MAC address of the node's Ethernet interface.
usage Number of virtual circuits currently active to the node.
Timer Number of seconds remaining until the node's service advertisement message will time out; this value is set to three times greater than the node's multicast timer value whenever a new service advertisement message is received.
sequence Sequence number received in the last service advertisement message. Nodes increment their sequence number when the contents of the service advertisement change.
changes Internal representation of what changed in the multicast message the last time the sequence number changed.
flags Internal representation of various state information about the node.
protocol LAT protocol version used by the node.
Recv and Xmit Number of messages, slots, and bytes received or transmitted to the node. The number of messages is the number of LAT virtual circuit messages. Each virtual circuit message contains some number of slots, which contain actual terminal data or control information.
Dups Number of duplicate virtual circuit messages received.
ReXmit Number of virtual circuit messages retransmitted.
Groups Group codes advertised by the node's service advertisement message.
Related Commands

show lat services
show service

show service

To display information about LAT learned services in a DECserver format, use the show service user EXEC command.

show service [service-name]
Syntax Description
service-name (Optional) Name of a specific LAT service.
Command Mode

User EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

The show service command without a service name displays a list of known LAT-learned services. When entered with the service-name argument, it displays a more detailed status of the named service. If there is no LAT-learned service by the specified name, a lookup is done for an IP host of that name.

Sample Display

The following is sample output from the show service command:

Router> show service
Service Name  Status  	    Identification
BLUE          	Available   Welcome to VAX/VMS V5.4
CHAOS   	      Available
MRL12   	      Available
MUDDY-RIVER  	 Available
STELLA-BLUE  	 Available   Welcome to VAX/VMS V5.4

The following is sample output from the show service command for a specified service:

Router> show service blue
Service BLUE - Available
Node Name   Status 	   Rating 	   Identification
BLUE   	     reachable 84        	Welcome to VAX/VMS V5.4 

Table 25 describes significant fields shown in the two previous displays.


Table 25: Show Service Field Descriptions
Field Description
Service Name Name of the service.
Status Status of the service. The status "Available" or "Unknown" is displayed when the command is entered without a service name. "Available," "Unknown," "Initializing," and "Unreachable" can be displayed when the command is entered with a LAT service name.
Identification Identification string.
Node Name Name of the nodes advertising the service.
Rating Rating of the service. Represented by an integer from 0 to 255, with the highest number being the preferred service. Used for load balancing.
Related Commands

show lat services
show lat sessions

show sessions

To display information about open LAT, Telnet, or rlogin connections, use the show sessions user EXEC command.

show sessions
Command Mode

User EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

This command display the host name, address, number of unread bytes for the user to receive, idle time, and connection name.

Sample Display

The following is sample output from the show sessions command:

sloth# show sessions
Conn Host                 Address          Byte    Idle  Conn Name
   1 MATHOM               192.31.7.21         0       0  MATHOM
*  2 CHAFF                131.108.12.19       0       0  CHAFF 

The asterisk (*) indicates the current terminal session.

Table 26 describes significant fields shown in the display.


Table 26: Show Sessions Field Descriptions
Field Description
Conn Name or address of the remote host to which the connection is made.
Host Remote host to which the router is connected through a Telnet session.
Address IP address of the remote host.
Byte Number of unread bytes displayed for the user to receive.
Idle Interval (in minutes) since data was last sent on the line.
Conn Name Assigned name of the connection.
Related Commands

resume
where

show tcp

To display the status of a TCP connection, use the show tcp user EXEC command.

show tcp [line-number]
Syntax Description
line-number (Optional) Displays (in octal) the status of the TCP connections for a particular line.
Command Mode

User EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show tcp command:

Router# show tcp
tty0, connection 1 to host cider
Connection state is ESTAB, I/O status: 1, unread input bytes: 0
Local host: 171.69.232.17, Local port: 11184
Foreign host: 171.69.1.137, Foreign port: 23
Enqueued packets for retransmit: 0, input: 0, saved: 0
Event Timers (current time is 67341276):
Timer:       Retrans   TimeWait    AckHold    SendWnd  KeepAlive
Starts:           30          0         32          0          0
Wakeups:           1          0         14          0          0
Next:              0          0          0          0          0
iss:   67317172  snduna:   67317228  sndnxt:   67317228     sndwnd:   4096
irs: 1064896000  rcvnxt: 1064897597  rcvwnd:       2144  delrcvwnd:      0
SRTT: 317 ms, RTTO: 900 ms, RTV: 133 ms, KRTT: 0 ms
minRTT: 4 ms, maxRTT: 300 ms, ACK hold: 300 ms
Flags: idle user, retransmission timeout
Datagrams (max data segment is 536 bytes):
Rcvd: 41 (out of order: 0), with data: 34, total data bytes: 1596
Sent: 57 (retransmit: 1), with data: 35, total data bytes: 55

Table 27 describes the following lines of output shown in the display:


Table 27: Show TCP Field Descriptions--First Section of Output
Field Description
tty0 Line number.
connection 1 Number identifying the TCP connection.
to host cider Name of the remote host to which the connection is made.
Connection state is ESTAB A connection progresses through a series of states. The states include the following:

  • LISTEN--Waiting for a connection request from any remote TCP port.

  • SYNSENT--Waiting for a matching connection request after having sent a connection request.

  • SYNRCVD--Waiting for a confirming connection request acknowledgment after having both received and sent a connection request.

  • ESTAB--Indicates an open connection; data received can be delivered to the user. This is the normal state for the data transfer phase.

  • FINWAIT1--Waiting for a connection termination request from the remote TCP host or an acknowledgment of the connection termination request previously sent.

  • FINWAIT2--Received an acknowledgment of the connection termination request that was sent.

  • CLOSEWAIT--Received a connection request.

  • CLOSING--Sent and received a connection termination request acknowledgment from the remote TCP host.

  • LASTACK--Received a connection termination request from the remote TCP host and the local user.

  • TIMEWAIT--Waiting for enough time to pass to be certain the remote TCP host has received the acknowledgment of its connection termination request.

  • CLOSED--Indicates no connection state at all.

For more information about connection states, see RFC 793, Transmission Control Protocol Functional Specification.

I/O status: 1 Number describing the internal status of the connection.
unread input bytes: 0 Number of bytes that the lower-level TCP processes have read, but the higher-level TCP processes have not yet processed.
Local host: 171.69.232.17 IP address of the network router.
Local port: 11184 Local port number derived from the following equation:
line-number + (512 * random-number).
The line number uses the lower nine bits; the other bits are random.
Foreign host: 171.69.1.137 IP address of the remote host to which the TCP connection was made.
Foreign port: 23 Port number for the remote host.
Enqueued packets for retransmit: 0 Number of packets waiting on the retransmit queue. These are packets on this TCP connection that have been sent but not yet acknowledged by the remote TCP host.
input: 0 Number of packets waiting on the input queue to be read by the user.
saved: 0 Number of received out-of-order packets waiting for all packets comprising the message to be received before they enter the input queue. For example, if packets 1, 2, 4, 5, and 6 have been received, packets 1 and 2 would enter the input queue, and packets 4, 5, and 6 would enter the saved queue.

The following line of output shows the current time according to the system clock of the local host.

Event Timers (current time is 67341276):

The following lines of output display the number of times that various local TCP timeout values were reached during a connection. In this example, the Cisco IOS software retransmitted once because it received no response from the remote host, and it transmitted an ACK-only segment 14 times because there was no data segment on which to piggyback. Table 28 describes the fields in the following lines of output:

Timer:       Retrans   TimeWait    AckHold    SendWnd  KeepAlive
Starts:           30          0         32          0          0
Wakeups:           1          0         14          0          0
Next:              0          0          0          0          0


Table 28: Show TCP Field Descriptions--Second Section of Output
Field Description
Timer Names of the timers in the display.
Retrans Determines how long a transmitted frame can remain unacknowledged before the Cisco IOS software polls for an acknowledgment.
TimeWait Determines how long the local TCP connection waits to be sure that the remote TCP host has received the acknowledgment of its connection termination request.
AckHold Number of times the system failed to piggyback data required on a TCP acknowledgment. Such piggybacking can significantly reduce network traffic.
SendWnd Timers for sending "zero window probes." Essentially, this field reflects how often users overload the remote host with data and how long it takes users to send it. For most normal Cisco IOS software applications, this value should be zero.
KeepAlive Determines the frequency (in seconds) at which the Cisco IOS software sends messages to itself (Ethernet and Token Ring) or to the other end (serial) to ensure that a network interface is alive. The keepalive interface configuration command is used to set this timer.
Starts Number of times the timer was started during this connection.
Wakeups Number of times the timer has expired.
Next Time that the timer expires.

The following lines of output display the sequence numbers that TCP uses to ensure sequenced, reliable transport of data. The router and remote host each use these sequence numbers for flow control and to acknowledge receipt of datagrams. Table 29 describes the fields in this output.

iss:   67317172  snduna:   67317228  sndnxt:   67317228     sndwnd:   4096
irs: 1064896000  rcvnxt: 1064897597  rcvwnd:       2144  delrcvwnd:      0


Table 29: Show TCP Field Descriptions--Sequence Numbers
Field Description
iss: 67317172 Initial send sequence number.
snduna: 67317228 Last send sequence number that the Cisco IOS software has sent but for which it has not received an acknowledgment.
sndnxt: 67317228 Sequence number that the Cisco IOS software will send next.
sndwnd: 4096 TCP window size of the remote host.
irs: 1064896000 Initial receive sequence number.
rcvnxt: 1064897597 Last receive sequence number that the Cisco IOS software has acknowledged.
rcvwnd: 2144 The Cisco IOS software's TCP window size.
delrcvwnd: 0 Delayed receive window--data that the Cisco IOS software has read from the connection, but has not yet subtracted from the receive window advertised to the remote host. The value in this field gradually increases until it is larger than a full-sized packet, at which point it is cleared and applied to the rcvwnd field.

The following lines of output show the values that the Cisco IOS uses to keep track of transmission times so that TCP can adjust to the network it is using. Table 30 describes the fields in this output.

SRTT: 317 ms, RTTO: 900 ms, RTV: 133 ms, KRTT: 0 ms
minRTT: 4 ms, maxRTT: 300 ms, ACK hold: 300 ms
Flags: higher precedence, idle user, retransmission timeout


Table 30: Show TCP Field Descriptions--Line Beginning with RTTO
Field Descriptions
SRTT: 317 ms Round-trip time estimate.
RTTO: 900 ms Round-trip timeout.
RTV: 133 ms Variance of the round-trip time.
KRTT: 0 ms New round-trip timeout (using the Karn algorithm). This field separately tracks the round-trip time of packets that have been retransmitted.
minRTT: 4 ms Smallest recorded round-trip timeout (hard wire value used for calculation).
maxRTT: 300 ms Largest recorded round-trip timeout.
ACK hold: 300 ms Time the Cisco IOS software will delay an acknowledgment so that it can piggyback data on it.

Flags

The following is a list of possible flags that describe your type of connection.

  • Idle user--The connection is idle because the user has suspended the connection.

  • Retransmission timeout--The connection will be dropped if retransmission continues to be unsuccessful.

  • Passive open--The connection was accepted by the router that issued the show tcp command.

  • Active--The connection was initiated by the router.

  • Keepalive running--TCP is searching for inactive clients.

  • Alias--The connection was made to an alias.

  • Timing out--The connection will soon be suspended due to excessive retransmissions.

  • Nagle--The local router is using the Nagle algorithm to maximize packet size
    (see RFC 896).

  • Net output pending--The Nagle algorithm is holding small packets from the TCP output queue and waiting to put them in to the network once the packet size is optimized.

  • Always push--The router sets the push bit when sending data packets.

  • Sync listen--The connection to the router is synchronized with the application.

  • Path mtu discovery--The connection is using path mtu discovery to determine its MSS.

For more information about these fields, refer to the article "Round Trip Time Estimation," by P. Karn and C. Partridge, ACM SIGCOMM-87, August 1987.

Table 31 describes the fields in the following lines of output from the show tcp command:

Datagrams (max data segment is 536 bytes):
Rcvd: 41 (out of order: 0), with data: 34, total data bytes: 1596
Sent: 57 (retransmit: 1), with data: 35, total data bytes: 55


Table 31: Show TCP Field Descriptions--Last Section of Output
Field Description
Datagrams Datagrams sent and received on the line.
Rcvd: 41(out of order: 0) Number of datagrams the local host has received during this connection (and the number of these datagrams that were out of order).
with data: 34 Number of datagrams that contained data.
total data bytes: 1596 Total number of bytes of data in the transmitted datagrams.
Sent: 57(and retransmitted: 1) Number of datagrams the local host sent during this connection (and the number of these datagrams that had to be retransmitted).
with data: 35 Number of transmitted datagrams that contained data.
total data bytes: 55 Total number of bytes of data in the transmitted datagrams.
Related Command

show tcp brief

show tcp brief

To view a summary of the TCP connection end points in the system, use the show tcp brief user EXEC command.

show tcp brief [all]
Syntax Description
all (Optional) Shows the status for all end points. End points in the LISTEN state are usually not shown.
Command Mode

User EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Sample Display

The following example is the output from the show tcp brief command after a user has connected to the router using Telnet:

Router# show tcp brief
TCB       Local Address           Foreign Address        (state)
609789AC  Router.cisco.com.23     cider.cisco.com.3733   ESTAB

Table 32 describes the fields shown in the example.


Table 32: Show TCP Brief Fields Descriptions
Field Description
TCB: 609789AC An internal identifier for the end point.
Local Address: Router.cisco.com.23 The local IP address and port.
Foreign Address: cider.cisco.com.3733 The foreign IP address and port.
(state): ESTAB The state of the connection. (See Table 31 for a description of connection states.)
Related Command

show tcp

show terminal

To display local terminal settings, use the show terminal user EXEC command.

show terminal
Command Mode

User EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

You can display information about the current terminal line, such as the line number, line status, modem state, and special characters set. This can be useful for changing lines to match expected settings using the local terminal parameter-setting tasks described in the section "Changing Terminal Parameters" in the "Configuring Terminal Lines and Modem Support" chapter in the Access Services Configuration Guide.

The display includes a comprehensive report on the terminal settings in effect, including the preferred transport protocol.


Note In screen output examples showing two caret (^^) symbols together, the first caret represents the Control key and the second caret represents the keystroke sequence Shift-6. The double caret combination (^^) means hold down the Control key while you press the Shift and the 6 key.
Sample Display

The following is sample output from the show terminal command:

sloth# show terminal
Line 2, Location: "", Type: ""
Length: 24 lines, Width: 80 columns
Baud rate (TX/RX) is 9600/9600
Status: Ready, Active, No Exit Banner
Capabilities: Enabled
Modem state: Ready
Special Chars: Escape  Hold  Stop  Start  Disconnect  Activation
                ^^x    none   -     -       none
Timeouts:      Idle EXEC    Idle Session   Modem Answer  Session   Dispatch
                never         never         0:00:15      not imp   not set
Session limit is not set.
Allowed transports are telnet rlogin.  Preferred is telnet
No output characters are padded

Table 33 describes the fields in the first three lines of show terminal output.


Table 33: Show Terminal Field Descriptions--First Three Lines of Output
Field Description
Line Current terminal line.
Location Location of the current terminal line, as specified by the location configuration command.
Type Type of the current terminal line, as specified by the line global configuration command.
Length Length of the terminal display.
Width Width of the terminal display.
Baud rate (TX/RX) Transmit rate and receive rate of the line.

The fourth line of sample output indicates the status of the line. In this example, Ready, Active, and No Exit Banner are possible values for the Status field.

Table 34 shows all possible values for the Status field.


Table 34: Show Terminal Field Description--Status Field
Field Description
Active A process is actively using the line.
Autobauding The line is running the autobaud process.
Carrier Dropped Some sense of "carrier" was dropped, so the line process should be killed.
Connected The line has at least one active connection.
Dialing Out A DDR asynchronous interface is dialing a remote site on the line.
Echo Off The line is not echoing what the user types (because a password must be entered, for example).
Escape Started The first character of the escape sequence was typed.
Escape Typed Both characters of the escape sequence have been typed.
Hanging Up The line state is "hanging up."
Hardware XON/XOFF The line uses a UART that supports XON/XOFF flow control in hardware. This does not mean that the line is currently using software flow control.
Hold Typed The user typed the "hold character" and the line is paused.
Idle The line modem state is "idle."
Idle Timeout An idle timeout has occurred.
Input Stopped The input was turned off because of to hardware flow control or overflow.
No Exit Banner The normal exit banner is not displayed on this line.
PSI Enabled The line is paying attention to typed escape characters.
Rcvd BREAK A BREAK sequence was received on the line.
Rcvd Command The line has received a special command sequence (^^B for SEND BREAK, for example).
Rcvd CR The last character received was a carriage return.
Ready The line state is "ready."
Ring Transition There was a transition on the RING signal on the line.
Send Break Soon A BREAK must be sent on the line soon.
Send XOFF Soon The buffers are full and an XOFF must be sent soon.
Sending Break A BREAK sequence is in the process of being sent on the line.
Sent XOFF The buffers were full, so an XOFF was sent.
Async Mode The line is running SLIP or PPP.

The fifth line of sample output indicates the status of the capabilities of the line; these capabilities correspond closely to configurable parameters that can be set using configuration commands. Table 35 describes possible values for the Capabilities field.


Table 35: Show Terminal Field Descriptions--Capabilities Field
Field Descriptions
Autobaud Full Range Corresponds to the autobaud line configuration command.
Character Padding Indicates that at least one pad configuration command was used.
Enabled Indicates that the user has "enabled" successfully.
EXEC Suppressed Corresponds to the no exec configuration command.
Hangup on Last Close Corresponds to the autohangup line configuration command.
Hardware Flowcontrol In Corresponds to the flowcontrol hardware in line configuration command.
Hardware Flowcontrol Out Corresponds to the flowcontrol hardware out line configuration command.
Insecure Corresponds to the insecure line configuration command.
Lockable Corresponds to the lockable line configuration command.
Modem Callin Corresponds to the modem callin line configuration command.
Modem Callout Corresponds to the modem callout line configuration command.
Modem CTS-Required Corresponds to the modem cts-required line configuration command.
Modem DTR-Active Corresponds to the modem dtr-active line configuration command.
Modem RI is CD Corresponds to the modem ri-is-cd line configuration command.
No Login Banner Corresponds to the no exec-banner line configuration command.
Notification Set Corresponds to the notify line configuration command.
Output Non-Idle Corresponds to the session-timeout N output line configuration command.
Permanent Async Corresponds to the dedicated-async line configuration command.
Private Line Corresponds to the private line configuration command.
Refuse Suppress-GA Corresponds to the telnet refuse line configuration command.
Receives Logging Output Corresponds to the monitor configuration line configuration command.
Refuse Telnet Echo Corresponds to the telnet refuse line configuration command.
Send BREAK on IP Corresponds to the telnet break-on-ip line configuration command.
SLIP allowed Corresponds to the slip address xxxx line configuration command.
Software Flowcontrol In Corresponds to the flowcontrol software in line configuration command.
Software Flowcontrol Out Corresponds to the flowcontrol software out line configuration command.
Telnet Transparent Mode Corresponds to the telnet transparent line configuration command.

The sixth line of sample output indicates the modem state. Possible values include Autobauding, Carrier Dropped, Hanging Up, Idle, and Ready.

The seventh and eighth lines of sample output indicate the special characters that can be entered to activate various terminal operations.


Note Where two caret (^^) symbols are shown together, the first caret represents the Control key and the second caret represents the keystroke sequence Shift-6. The double caret combination (^^) means hold down the Control key while you press the Shift and the 6 key. The none or hyphen (-) values imply that no special characters are set.

The ninth and tenth lines of output indicate the timeout values that have been configured for the line:

Timeouts:      Idle EXEC    Idle Session   Modem Answer  Session   Dispatch
                never         never         0:00:15      not imp   not set

Table 36 describes the fields in the preceding lines of output.


Table 36: Show Terminal Field Descriptions--Timeouts Fields
Field Descriptions
Idle EXEC Interval the EXEC command interpreter waits for user input before either resuming the current connection, or if no connections exist, returning the terminal to the idle state and disconnecting the incoming session. This interval is set using the exec-timeout line configuration command.
Idle Session Interval that the Cisco IOS software waits for traffic before closing the connection to a remote computer and returning the terminal to an idle state. This interval is set using the session-timeout line configuration command.
Modem Answer Interval during which the Cisco IOS software raises DTR in response to RING and the modem response to CTS. This interval is set using the modem answer-timeout line configuration command.
Session Not implemented in this release.
Dispatch Number of milliseconds the Cisco IOS software waits after putting the first character into a packet buffer before sending the packet. This interval is set using the dispatch-timeout configuration command.

The last three lines of output indicate how various options have been configured:

Session limit is not set.
Allowed transports are telnet rlogin.  Preferred is telnet
No output characters are padded

show users

To display information about the active lines on the router, use the show users user EXEC command.

show users [all]
Syntax Description
all (Optional) Specifies that all lines be displayed, regardless of whether anyone is using them.
Command Mode

User EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

This command displays the line number, connection name, idle time, and terminal location.

Sample Display

The following is sample output from the show users command:

Router# show users
     	Line          	User	           Host(s)	       Idle Location
     	0 con 0	                      	idle
*    	2 vty 0       	rose           	idle           	0   BASHFUL.CISCO.COM

The following is sample output from the show users all command:

Router# show users all
	   Line      	User         	Host(s)     	Idle  Location
*  	0 vty 0	   rose         	idle         0    BASHFUL.CISCO.COM
   	1 vty 1
	   2 con 0
	   3 aux 0
	   4 vty 2

The asterisk (*) indicates the current terminal session.

Table 37 describes significant fields shown in the displays.


Table 37: Show Users Field Descriptions
Field Description
Line Contains three subfields.

  • The first subfield (0 in the sample output) is the absolute line number.

  • The second subfield (vty) indicates the type of line. Possible values follow:

con--Console
aux--Auxiliary port
tty--Asynchronous terminal port
vty--Virtual terminal

  • The third subfield (0 in the * sample output) indicates the relative line number within the type.

User

User using the line. If no user is listed in this field, no one is using the line.
Host(s) Host to which the user is connected (outgoing connection). A value of idle means that there is no outgoing connection to a host.
Idle Interval (in minutes) since the user has entered something.
Location Either the hard-wired location for the line or, if there is an incoming connection, the host from which incoming connection came.
Related Command

show users

show x25 pad

To display information about current open connections, including packet transmissions, X.3 parameter settings, and the current status of virtual circuits, use the show lat services user EXEC command.

show x25 pad
Command Mode

User EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Sample Display

The following is sample output from the show x25 pad command:

sloth# show x25 pad
tty2, Incoming PAD connection
Total input: 61, control 6, bytes 129. Queued: 0 of 7 (0 bytes).
Total output: 65, control 6, bytes 696.
Flags: 1,   State: 3,   Last error: 1
 ParamsIn:  1:1, 2:0, 3:2, 4:1, 5:1, 6:0, 7:21,
    8:0, 9:0, 10:0, 11:14, 12:0, 13:0, 14:0, 15:1,
    16:127, 17:21, 18:18, 19:0, 20:0, 21:0, 22:0,
 ParamsOut:  1:1, 2:1, 3:2, 4:1, 5:0, 6:0, 7:4,
    8:0, 9:0, 10:0, 11:14, 12:0, 13:0, 14:0, 15:0,
    16:127, 17:21, 18:18, 19:0, 20:0, 21:0, 22:0,
 LCI: 1,  State: D1,  Interface: Serial0
 Started 0:11:10, last input 0:00:16, output 0:00:16
 Connected to 313700540651
 Window size input: 7, output: 7
 Packet size input: 512, output: 512
 PS: 1  PR: 5  ACK: 5  Remote PR: 1  RCNT: 0  RNR: FALSE
 Retransmits: 0  Timer (secs): 0  Reassembly (bytes): 0
 Held Fragments/Packets: 0/0
 Bytes 696/129 Packets 65/61 Resets 0/0 RNRs 0/0 REJs 0/0 INTs 0/0

Table 38 describes significant fields shown in the output in the display.


Table 38: Show X.25 Pad Field Descriptions
Field Description
Total input/output Number of packets received or sent for the connection.
Control Number of packets with Qbit set (X.29 control packets).
Bytes Number of bytes in each direction.
Queued Number of unread packets waiting for the connection.
Waiting to send Local data packet bit not sent (part of a line).
Flags, state, last error Displays data for detecting errors and tracing initialization status. Only useful to your Cisco-certified technical support personnel.
Params In Parameters read from the PAD at the start of the connection.
ParamsOut Active X.3 parameters.
The line beginning LCI Status of the X.25 virtual circuit associated with the PAD connection. This is the same display that the show x25 vc command shows.

show xremote

To list XRemote connections and monitor XRemote traffic through the networking hardware, use the show xremote user EXEC command.

show xremote [line]
Syntax Description
line (Optional) Name or number of the line.
Command Mode

User EXEC

Usage Guidelines

This command first appeared Cisco IOS Release 11.2.

This command provides XRemote parameters applied to the entire system and statistics that are pulled for all active XRemote connections.

Sample Display

The following is sample output from the show xremote command:

Router> show xremote 
XRemote server-wide parameters:
  Font buffersize:     72000              Font retries: 3
  Font memory errors:  0
TFTP font load statistics for host 131.108.1.111:
  Bytes read:          2697239            Files read: 258
  Network errors:      4                  File errors: 0
LAT font load statistics for service WHEEL, incarnation 5:
 Bytes read            182401             Files read: 14
 Protocol errors:      0                  Insufficient memory: 0
XRemote statistics for tty2:
  Current clients:     9                  Total clients: 17
  Requesting client:   5                  Current request size: 0
  Replying client:     6                  Current reply size: 0
  XDM state:           10                 Next timeout: 172460
  Retransmit counter:  0                  Local UDP port: 53616
  Keepalive dormancy:  180                Session id: 94
  Unread input:        0                  Unwritten output: 0
  Input buffer size:   1024               Output buffer size: 108
  Protocol version:    2                  Line state: Connected
  Transmit packets:    50768              Receive packets: 49444
  Transmit errors:     0                  Receive errors: 37
  Retransmissions:     403                Receive out of sequence: 76
  Round trip time:     383                Retransmit interval: 766
  Transmit window:     7                  Receive window: 7
  Transmit next:       6                  Receive next: 3
  Transmit unacked:    6                  Receive unacked: 0
  Connection 0 - TCP connection from 131.108.1.55  [Display Manager]
    Client state:       CS_ACTIVE         Byte order: MSBfirst
    Unread input:       0                 Unwritten output: 0
    Input buffer size:  1024              Output buffer size: 1024
  Connection 1 - TCP connection from 131.108.1.55
    Client state:       CS_ACTIVE         Byte order: MSBfirst
    Unread input:       0                 Unwritten output: 0
    Input buffer size:  1024              Output buffer size: 1024
  Connection 2 - TCP connection from 131.108.1.55
    Client state:       CS_ACTIVE         Byte order: MSBfirst
    Unread input:       0                 Unwritten output: 0
    Input buffer size:  1024              Output buffer size: 1024
  Connection 3 - LAT connection from WHEEL
    Client state:       CS_ACTIVE         Byte order: LSBfirst
    Unread input:       0                 Unwritten output: 0
    Input buffer size:  1024              Output buffer size: 1024

Table 39 describes some of the fields shown in the sample output.


Table 39: Show XRemote Field Descriptions
Field Description
XRemote server-wide parameters XRemote parameters that apply to the Cisco IOS software.
Font buffersize XRemote font buffer size, as specified using the xremote tftp buffersize global configuration command.
Font retries Number of retries that the font loader (host) attempts before declaring an error condition.
Font memory errors Number of font memory error conditions that have been declared for the Cisco IOS software.
TFTP font load statistics XRemote statistics for fonts that have been loaded from a TFTP font server at the IP address shown.
Bytes read Number of bytes the host read to load the fonts.
Files read Number of files the host read to load the fonts.
Network errors Errors that arise from TFTP network connection failures.
File errors Bad-format font file errors.
Protocol errors LAT font loading protocol errors when talking to the font server on VMS.
XRemote statistics for tty XRemote statistics for the specified line.
Current clients Number of clients using this line for active Xremote sessions.
Total clients Number of clients using this line for active Xremote sessions.
Requesting client Number of clients requesting Xremote service.
Retransmit counter Number of times that an Xremote connection request was retransmitted.
Local UDP port Number assigned to the local UDP port.
Keepalive dormancy Amount of time between keepalive messages.
Client state XRemote state.
Byte order Byte ordering used between the X Server (the X Terminal) and the X Client (the UNIX host).
LSBfirst Little Endian byte ordering.
MSBfirst Big Endian byte ordering.
Related Command

show xremote line

show xremote line

To list XRemote connections and monitor XRemote traffic for specific lines on a router, use the show xremote line user EXEC command.

show xremote line [number]
Syntax Description
number (Optional) Decimal value representing virtual terminal lines on a server.
Default

None

Command Mode

User EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Sample Display

The following is sample output from a show xremote line command when XRemote is enabled in the Cisco IOS software and XRemote sessions are active. Only information about an individual terminal line is provided. Table 39 describes the fields in the display:

Router# show xremote line 3 
Xremote statistics for tty3:
  Current clients:     11                 Total clients: 19
  Requesting client:   10                 Current request size: 0
  Replying client:     10                 Current reply size: 0
  XDM state:           10                 Next timeout: 173304
  Retransmit counter:  0                  Local UDP port: 28384
  Keepalive dormancy:  180                Session id: 29
  Unread input:        0                  Unwritten output: 0
  Input buffer size:   1024               Output buffer size: 108
  Protocol version:    2                  Line state: Connected
  Transmit packets:    28875              Receive packets: 18644
  Transmit errors:     0                  Receive errors: 13
  Retransmissions:     53                 Receive out of sequence: 41
  Round trip time:     384                Retransmit interval: 768
  Transmit window:     7                  Receive window: 7
  Transmit next:       2                  Receive next: 7
  Transmit unacked:    2                  Receive unacked: 0
  Connection 0 - TCP connection from 131.108.1.27  [Display Manager]
    Client state:       CS_ACTIVE         Byte order: MSBfirst
    Unread input:       0                 Unwritten output: 0
    Input buffer size:  1024              Output buffer size: 1024
  Connection 1 - TCP connection from 131.108.1.27
    Client state:       CS_ACTIVE         Byte order: MSBfirst
    Unread input:       0                 Unwritten output: 0
    Input buffer size:  1024              Output buffer size: 1024
  Connection 2 - TCP connection from 131.108.1.27
    Client state:       CS_ACTIVE         Byte order: MSBfirst
    Unread input:       0                 Unwritten output: 0
    Input buffer size:  1024              Output buffer size: 1024
Related Command

show xremote

slip

To start a serial connection to a remote host by using SLIP, use the slip EXEC command.

slip [/default] {remote-ip-address | remote-name} [@tacacs-server] [/routing]} [/compressed]
Syntax Description
/default (Optional) Makes a SLIP connection when a default address has been configured.
remote-ip-address IP address of the client workstation or PC.
remote-name Name of the client workstation or PC.
@tacacs-server (Optional) IP address or IP host name of the TACACS server to which your TACACS authentication request is sent.
/routing (Optional) Indicates that the remote system is a router. Line must be configured for asynchronous routing using SLIP encapsulation.
/compressed (Optional) Indicates that IP header compression should be negotiated.
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

When you connect from a remote node computer to the EXEC facility on a router and want to connect from the router to a device on the network, issue the slip command.

If you specify an address for the TACACS server by using /default or tacacs-server, the address must be the first parameter in the command after you enter slip. If you do not specify an address or enter /default, you are prompted for an IP address or host name. You can enter /default at this point.

If you do not use the tacacs-server argument to specify a TACACS server for SLIP address authentication, the TACACS server specified at login (if any) is used for the SLIP address query.

To optimize bandwidth on a line, SLIP enables compression of the SLIP packets using Van Jacobson TCP header compression as defined in RFC 1144.

Your system administrator must configure the system with the ip tcp header-compression passive command for the /compressed command option to be valid in EXEC mode. The ip tcp header-compression command forces header compression on or off. The default is to not compress the packets. The configuration file must have header compression on and the slip /compressed EXEC command must be entered for header compression to occur.

To terminate a session initiated with the slip command, disconnect from the device on the network using the command specific to that device. Then, exit from the EXEC by using the exit command.

Examples

The following example illustrates how to make a connection when a default IP address is assigned. Once a correct password is entered, you are placed in SLIP mode, and the IP address is displayed.

Router> slip
Password:
Entering SLIP mode.
Your IP address is 192.31.7.28, MTU is 1524 bytes

The following example illustrates the prompts displayed and the response required when you use dynamic addressing to assign the SLIP address:

Router> slip
IP address or hostname? 192.31.6.15
Password:
Entering SLIP mode
Your IP address is 192.31.6.15, MTU is 1524 bytes

In the preceding example, the address 192.31.6.15 has been assigned as the default. Password verification is still required before SLIP mode can be enabled.

Router> slip /default
Password:
Entering SLIP mode
Your IP address is 192.31.6.15, MTU is 1524 bytes

The following example illustrates the implementation of header compression on the interface with the IP address 128.66.2.1:

Router> slip 128.66.2.1 /compressed 
Password:
Entering SLIP mode.
Interface IP address is 128.66.2.1, MTU is 1500 bytes.
Header compression will match your system.

In the preceding example, the interface is configured for ip tcp header-compression passive, which permits the user to enter the /compressed keyword at the EXEC mode prompt. The message "Header compression will match your system" indicates that the user specified compression. If the line was configured for ip tcp header-compression on, this line would read "Header compression is On."

The following example specifies a TACACS server named server1 for address authentication:

Router> slip 1.0.0.1@server1
Password:
Entering SLIP mode.
Interface IP address is 1.0.0.1, MTU is 1500 bytes
Header compression will match your system. 

systat

The show users command replaces the systat command. Refer to the description of the show users command for more information.

telnet

To log on to a host that supports Telnet, use the telnet EXEC command.

telnet host [port] [keyword] 
Syntax Description
host A host name or an IP address.
port (Optional) A decimal TCP port number; the default is the Telnet router port (decimal 23) on the host.
keyword (Optional) One of the options listed in Table 40.


Table 40: Telnet Connection Options
Option Description
/debug Enables Telnet debugging mode.
/line Enables Telnet line mode. In this mode, the Cisco IOS software sends no data to the host until you press Return. You can edit the line using the standard Cisco IOS software command-editing characters. The /line keyword is a local switch; the remote router is not notified of the mode change.
/noecho Causes the connection to start in a mode where it does NOT echo characters typed by the user (the telnet spec defines local echoing as the default, this changes the default to NO local echoing). This does not prevent the remote site from doing echoing, and does not prevent local echoing from being negotiated at a later time. It is primarilly used when talking to systems that do not correctly implement a telnet server.
/route path Specifies loose source routing. The path argument is a list of host names or IP addresses that specify network nodes and ends with the final destination.
/source-interface Causes the ip source address used by the router for the tcp connection to be taken from the interface specified. See also "ip telnet source-interface" config command.
/stream Turns on stream processing, which enables a raw TCP stream with no Telnet control sequences. A stream connection does not process Telnet options and can be appropriate for connections to ports running UUCP and other non-Telnet protocols.
port-number Port number.
bgp Border Gateway Protocol.
chargen Character generator.
cmd rcmd Remote commands.
daytime Daytime.
discard Discard.
domain Domain Name Service.
echo Echo.
exec EXEC.
finger Finger
ftp File Transfer Protocol.
ftp-data FTP data connections (used infrequently).
gopher Gopher.
hostname NIC hostname server.
ident Ident Protocol.
irc Internet Relay Chat
klogin Kerberos login.
kshell Kerberos shell.
login Login (rlogin).
lpd Printer service.
nntp Network News Transport Protocol.
node Connect to a specific LAT node
pop2 Post Office Protocol v2.
pop3 Post Office Protocol v3.
port Destination LAT port name.
smtp Simple Mail Transport Protocol.
sunrpc Sun Remote Procedure Call.
syslog Syslog.
tacacs Specify TACACS security.
talk Talk.
telnet Telnet.
time Time.
uucp Unix-to-Unix Copy Program.
whois Nickname.
www World Wide Web (HTTP).
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

With the Cisco IOS implementation of TCP/IP, you are not required to enter the connect or telnet commands to establish a Telnet connection. You can just enter the learned host name--as long as the following conditions are met:

To display a list of the available hosts, use the show hosts command. To display the status of all TCP connections, use the show tcp command.

The Cisco IOS software assigns a logical name to each connection, and several commands use these names to identify connections. The logical name is the same as the host name, unless that name is already in use, or you change the connection name with the name-connection EXEC command. If the name is already in use, the Cisco IOS software assigns a null name to the connection.

The Telnet software supports special Telnet commands in the form of Telnet sequences that map generic terminal control functions to operating system-specific functions. To issue a special Telnet command, enter the escape sequence and then a command character. The default escape sequence is Ctrl-^ (press and hold the Control and Shift keys and the 6 key). You can enter the command character as you hold down Ctrl or with Ctrl released; you can use either uppercase or lowercase letters. Table 41 lists the special Telnet escape sequences.


Table 41: Special Telnet Escape Sequences
Task Escape Sequence1
Break Ctrl-^ b
Interrupt Process (IP) Ctrl-^ c
Erase Character (EC) Ctrl-^ h
Abort Output (AO) Ctrl-^ o
Are You There? (AYT) Ctrl-^ t
Erase Line (EL) Ctrl-^ u

1 The caret (^) symbol refers to Shift-6 on your keyboard.

At any time during an active Telnet session, you can list the Telnet commands by pressing the escape sequence keys followed by a question mark at the system prompt:

Ctrl-^ ?

A sample of this list follows. In this sample output, the first caret (^) symbol represents the Control key, while the second caret represents Shift-6 on your keyboard:

Router> ^^?
[Special telnet escape help]
^^B  sends telnet BREAK
^^C  sends telnet IP
^^H  sends telnet EC
^^O  sends telnet AO
^^T  sends telnet AYT
^^U  sends telnet EL 

You can have several concurrent Telnet sessions open and switch back and forth between them. To open a subsequent session, first suspend the current connection by pressing the escape sequence (Ctrl-Shift-6 then x [Ctrl^x] by default) to return to the system command prompt. Then open a new connection with the telnet command.

To terminate an active Telnet session, issue any of the following commands at the prompt of the device to which you are connecting:

close
disconnect
exit
logout
quit

Examples

The following example routes packets from the source system host1 to kl.sri.com, then to 10.1.0.11, and finally back to host1:

Router> telnet host1 /route:kl.sri.com 10.1.0.11 host1
 

The following example connects to a host with logical name host1:

Router> host1
Related Commands

connect
rlogin

terminal data-character-bits

To set the number of data bits per character that are interpreted and generated by the Cisco IOS software for the current line and session, use the terminal data-character-bits EXEC command.

terminal data-character-bits {7 | 8}
Syntax Description
7 Seven data character bits.
8 Eight data character bits.
Default

8 data bits per character

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

This command first appeared in Cisco IOS Release 9.1.

This command is used primarily to strip parity from X.25 connections on IGS or Cisco 3000 routers with the protocol translation software option. The terminal data-character-bits command does not work on hard-wired lines.

Example

The following example sets the data bits per character on the current line to 7:

Router> terminal data-character-bits 7
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as shown by the dagger (+).

data-character-bits +

terminal databits

To change the number of data bits per character for the current terminal line for this session, use the terminal databits EXEC command.

terminal databits {5 | 6 | 7 | 8}
Syntax Description
5 Five data bits per character.
6 Six data bits per character.
7 Seven data bits per character.
8 Eight data bits per character.
Default

8 data bits per character

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Communication protocols provided by devices such as terminals and modems often require a specific data bit setting. The terminal databits command can be used to mask the high bit on input from devices that generate 7 data bits with parity. If parity is being generated, specify 7 data bits per character. If no parity generation is in effect, specify 8 data bits per character. The other keywords (5 and 6) are supplied for compatibility with older devices and are generally not used.

Example

The following example shows how to change the databits per character to seven:

Router> terminal databits 7
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as shown by the dagger (+).

databits +

terminal dispatch-character

To define a character that causes a packet to be sent for the current session, use the terminal dispatch-character EXEC command.

terminal dispatch-character ASCII-number1 [ASCII-number2 . . . ASCII-number]
Syntax Description
ASCII-number The ASCII decimal representation of the character, such as Return (ASCII character 13) for line-at-a-time transmissions. The command can take multiple arguments, so you can define any number of characters as the dispatch character.
Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

At times, you might want to queue up a string of characters until they fill a complete packet and then transmit the packet to a remote host. This can make more efficient use of a line, because the access server or router normally dispatches each character as it is entered.

Example

The following example defines the characters Ctrl-D (ASCII decimal character 4) and Ctrl-Y (ASCII decimal character 25) as the dispatch characters:

Router> terminal dispatch-character 4 25
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as shown by the dagger (+).

dispatch-character +

terminal dispatch-timeout

To set the character dispatch timer for the current terminal line for the current session, use the terminal dispatch-timeout EXEC command.

terminal dispatch-timeout milliseconds
Syntax Description
milliseconds An integer that specifies the number of milliseconds that the router waits after it puts the first character into a packet buffer before sending the packet. During this interval, more characters can be added to the packet, which increases processing efficiency of the remote host.
Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Use this command to increase the processing efficiency of the remote host.


Note The router's response might appear intermittent if the timeout interval is greater than 100 milliseconds and remote echoing is used.
Example

The following example sets the dispatch timer to 80 milliseconds:

Router> terminal dispatch-timeout 80
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as shown by the dagger (+).

dispatch-timeout +

terminal download

To temporarily set the ability of a line to act as a transparent pipe for file transfers for the current session, use the terminal download EXEC command.

terminal download
Default

Disabled

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

You can use this feature to run a program such as KERMIT, XMODEM, or CrossTalk that downloads a file across an access server or router line. This command sets up the terminal line to transmit data and is equivalent to entering all the following commands:

terminal escape-character

To set the escape character for the current terminal line for the current session, use the terminal escape-character EXEC command.

terminal escape-character ASCII-number
Syntax Description
ASCII-number Either the ASCII decimal representation of the escape character or a control sequence (Ctrl-P, for example). Entering the escape character followed by X returns you to the EXEC when you are connected to another computer. See the "ASCII Character Set" appendix in the Configuration Fundamentals Command Reference for a list of ASCII characters.
Default

Ctrl-^ (which is Ctrl-Shift-6)

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

This command is useful, for example, if you have the default escape character defined for a different purpose in your keyboard file. Entering the escape character followed by the X key returns you to EXEC mode when you are connected to another computer.


Note The Break key cannot be used as an escape character on the console terminal because the operating software interprets BREAK as an instruction to halt the system.
Example

The following example sets the escape character to Ctrl-P (ASCII decimal 16):

Router> terminal escape-character 16 
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as shown by the dagger (+).

escape-character +

terminal exec-character-bits

To locally change the ASCII character set used in EXEC and configuration command characters for the current session, use the terminal exec-character-bits EXEC command.

terminal exec-character-bits {7 | 8}
Syntax Description
7 Selects the 7-bit ASCII character set.
8 Selects the full 8-bit character set.
Default

7-bit ASCII character set (unless set otherwise in global configuration mode)

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

This EXEC command overrides the default-value exec-character-bits global configuration command. Configuring the EXEC character width to 8 bits enables you to add special graphical and international characters in banners, prompts, and so forth.

When the user exits the session, the character width is reset to the default value established by the default value EXEC-character-bits global configuration command. However, setting the EXEC character width to 8 bits can also cause failures. If a user on a terminal that is sending parity enters the help command, an "unrecognized command" message appears because the system is reading all 8 bits, and the eighth bit is not needed for the help command.

Example

The following example temporarily configures a router to use a full 8-bit user interface for system banners and prompts, allowing the use of additional graphical and international characters.

terminal exec-character-bits 8
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as shown by the dagger (+).

exec-character-bits +

terminal flowcontrol

To set flow control for the current terminal line for the current session, use the terminal flowcontrol EXEC command.

terminal flowcontrol {none | software [in | out] | hardware}
Syntax Description
none Prevents flow control.
software Sets software flow control.
[in | out] (Optional) Specifies the direction: in causes the router to listen to flow control from the attached device, and out causes the router to send flow control information to the attached device. If you do not specify a direction, both directions are assumed.
hardware Sets hardware flow control. For information about setting up the RS-232 line, see the manual that was shipped with your product.
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Flow control enables you to regulate the rate at which data can be transmitted from one point so that it is equal to the rate at which it can be received at another point. Flow control protects against loss of data because the terminal is not capable of receiving data at the rate it is being sent. You can set up data flow control for the current terminal line in one of two ways: software flow control, which you do with control key sequences, and hardware flow control, which you do at the device level.

For software flow control, the default stop and start characters are Ctrl-S and Ctrl-Q (XOFF and XON). You can change them with the terminal stop-character and terminal start-character commands.

Example

The following example sets incoming software flow control:

Router> terminal flowcontrol software in 
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as shown by the dagger (+).

flowcontrol +

terminal hold-character

To set or change the hold character for the current session, use the terminal hold-character EXEC command. Use the terminal no hold-character command to delete the hold character.

terminal hold-character ASCII-number
Syntax Description
ASCII-number Either the ASCII decimal representation of the hold character or a control sequence (for example, Ctrl-P). By default, no local hold character is set. The Break character is represented by zero; NULL cannot be represented.
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You can define a local hold character that temporarily suspends the flow of output on the terminal. When information is scrolling by too fast, you can enter the hold character to pause the screen output, then enter any other character to resume the flow of output.

You cannot suspend output on the console terminal. To send the hold character to the host, precede it with the escape character.

Example

The following example removes the previously set hold character:

Router> terminal no hold-character 
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

hold-character +

terminal keymap-type

To specify the current keyboard type for the current session, use the terminal keymap-type EXEC command.

terminal keymap-type keymap-name
Syntax Description
keymap-name Name defining the current keyboard type.
Default

VT100

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

You must use this command when you are using a keyboard other than the default of VT100. The system administrator can define other keyboard types and give you their names.

Example

The following example specifies a VT220 keyboard as the current keyboard type:

Router> terminal keymap-type vt220

terminal lat

To temporarily define the list of services to which you or another user can connect, use the terminal lat EXEC command.

terminal lat remote-modification
terminal lat
out-group {groupnumber [start-end] [disabled | enabled]}
Syntax Description
out-group Defines a group list for outgoing user-initiated connections.
remote-modification Sets the line to be remotely modifiable.
groupnumber [start-end] Number of the group that has access to the system through the specified line. This number is identified by the system administrator. You also can specify a range of group numbers. Separate the beginning and end of the range with a hyphen.
disabled Incrementally removes specified groups from list.
enabled Incrementally adds specified groups to list.
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

To temporarily define the list of services to which you or another user can connect, you define the group code lists used for connections from specific lines. You limit the connection choices for an individual line by defining the group code lists for an outgoing connection. When a user initiates a connection with a LAT host, the user's line must share a common group number with the remote LAT host before a connection can be made.

The group code range entered in this command must fall within the group code range already configured for the line.

Example

The following example defines a group code list for the outgoing group 4:

Router> terminal lat out-group 4, 6-189 
Related Commands

connect
lat

terminal length

To set the number of lines on the current terminal screen for the current session, use the terminal length EXEC command.

terminal length screen-length
Syntax Description
screen-length Your desired number of lines on the screen. The router uses this value to determine when to pause during multiple-screen output. A value of zero prevents the router from pausing between screens of output. When the output exceeds the screen length, it scrolls past.
Default

24 lines

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Some types of terminal sessions do not require you to specify the screen length because the screen length specified can be learned by some remote hosts. For example, the rlogin protocol uses the screen length to set up terminal parameters on a remote UNIX host.

Example

The following example prevents the router from pausing between multiple screens of output:

Router> terminal length 0 
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

length +

terminal monitor

To display debug command output and system error messages for the current terminal and session, use the terminal monitor EXEC command.

terminal monitor
Default

Disabled

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Remember that all terminal parameter-setting commands are set locally and do not remain in effect after a session is ended. You must perform this task at the privileged-level EXEC prompt at each session to see the debugging messages.

For more information about privileged-level EXEC mode, refer to the chapter "Understanding the User Interface" in the Configuration Fundamentals Configuration Guide.

terminal notify

To configure a line to inform a user who has multiple concurrent Telnet connections when output is pending on a connection other than the current one, use the terminal notify EXEC command.

terminal notify
Default

none

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

You might want to know, for example, when another connection receives mail or a message.

Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

notify +

terminal padding

To change the character padding on a specific output character for the current session, use the terminal padding EXEC command.

terminal padding ASCII-number count
Syntax Description
ASCII-number The ASCII decimal representation of the character.
count The number of NULL bytes sent after that character, up to 255 padding characters in length.
Default

No padding

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Character padding adds a number of null bytes to the end of the string and can be used to make a string an expected length for conformity.

Example

The following example pads Ctrl-D (ASCII decimal character 4) with 164 NULL bytes:

Router> terminal padding 4 164 
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

padding +

terminal parity

To define the generation of the parity bit for the current terminal line for the current session, use the terminal parity EXEC command.

terminal parity {none | even | odd | space | mark}
Syntax Description
none No parity. This is the default.
even Even parity.
odd Odd parity.
space Space.
mark Mark.
Default

none

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Communication protocols provided by devices such as terminals and modems often require a specific parity bit setting.

Example

The following example shows how to set the parity bit to odd:

Router> terminal parity odd
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

parity +

terminal rxspeed

To set the terminal receive speed (how fast information is sent to the terminal) for the current line and session, use the terminal rxspeed EXEC command.

terminal rxspeed bps
Syntax Description
bps Baud rate in bits per second (bps). Table 42 lists line speeds for supported routers.
Default

9600 bps

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Use Table 42 as a guide for setting the line speeds.


Table 42: Router Line Speeds in Bits per Second
Server Product Model Baud Rates
Cisco 2500 access servers Any speed from 50 to 115200.
Cisco 2500 routers 75, 110, 134, 150, 300, 600, 1200, 2000, 2400, 4800, 1800, 9600, 19200, 38400.
Cisco 4000 family 75, 110, 134, 150, 300, 600, 1200, 2000, 2400, 4800, 1800, 9600, 19200, and 38400.
Cisco 7000 family 50, 75, 110, 134, 150, 200, 300, 600, 1050, 1200, 2000, 2400, 4800, 9600, 19200, and 38400.
Example

The following example sets the current auxiliary line receive speed to 115200 bps:

AS5200> terminal rxspeed 115200
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

rxspeed +

terminal special-character-bits

To change the ASCII character widths to accept special characters for the current terminal line and session, use the terminal special-character-bits EXEC command.

terminal special-character-bits {7 | 8}
Syntax Description
7 Selects the 7-bit ASCII character set.
8 Selects the full 8-bit ASCII character set. Configuring the width to 8 bits enables you to use twice as many special characters as with the 7-bit setting. This selection enables you to add special graphical and international characters in banners, prompts, and so forth.
Default

7-bit ASCII character set

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

This command is useful, for example, if you want the router to provide temporary support for international character sets. It overrides the default-value special-character-bits global configuration command and is used to compare character sets typed by the user with the special character available during a data connection, which includes software flow control and escape characters.

When you exit the session, the character width is reset to the default value established by the global configuration command. However, setting the EXEC character width to eight bits can cause failures. If a user on a terminal that is sending parity enters the help command, an "unrecognized command" message appears because the Cisco IOS software is reading all eight bits, and the eighth bit is not needed for the help command.

Example

The following example temporarily configures a router to use a full 8-bit user interface for system banners and prompts. When you exit the system, character width is reset to the width established by the default-value exec-character-bits global configuration command.

Router> terminal special-character-bits 8
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

special-character-bits +

terminal speed

To set the transmit and receive speeds of the current terminal line for the current session, use the terminal speed EXEC command.

terminal speed bps
Syntax Description
bps The baud rate in bits per second (bps).
Default

9600 bps

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Set the speed to match the transmission rate of whatever device you have connected to the port. Some baud rates available on devices connected to the port might not be supported on the router. The router indicates whether the speed you selected is not supported.

Example

The following example restores the transmit and receive speed on the current line to 9600 bps.

Router> terminal speed 9600 
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

speed +

terminal start-character

To change the flow control start character for the current session, use the terminal start-character EXEC command.

terminal start-character ASCII-number
Syntax Description
ASCII-number The ASCII decimal representation of the start character.
Default

Ctrl-Q (ASCII decimal character 17)

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

The flow control start character signals the start of data transmission when software flow control is in effect.

Example

The following example changes the start character to Ctrl-O (ASCII decimal character 15):

Router> terminal start-character 15
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

start-character +

terminal stop-character

To change the flow control stop character for the current session, use the terminal stop-character EXEC command.

terminal stop-character ASCII-number
Syntax Description
ASCII-number The ASCII decimal representation of the stop character.
Default

Ctrl-S (ASCII character 19)

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

The flow control stop character signals the end of data transmission when software flow control is in effect.

Example

The following example changes the stop character to Ctrl-E (ASCII character 5).

Router> terminal stop-character 5
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

stop-character +

terminal stopbits

To change the number of stop bits transmitted per byte by the current terminal line during an active session, use the terminal stopbits EXEC command.

terminal stopbits {1 | 1.5 | 2}
Syntax Description
1 One stop bit.
1.5 One and a half stop bits.
2 Two stop bits.
Default

2

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Communication protocols provided by devices such as terminals and modems often require a specific stop-bit setting.

Example

The following example illustrates how to change the stop bits to one:

Router> terminal stopbits 1 
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

stopbits +

terminal telnet transparent

To cause the current terminal line to send a Return character (CR) as a CR followed by a NULL instead of a CR followed by a LINE FEED (LF) for the current session, use the terminal telnet transparent EXEC command.

terminal telnet transparent
Default

CR followed by a LINE FEED (LF)

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

The end of each line typed at the terminal is ended with a Return (CR). This command permits interoperability with different interpretations of end-of-line demarcation in the Telnet protocol specification.


Note This command applies only to access server products. It is not supported on standalone routers.

terminal telnet break-on-ip

To cause the access server to generate a hardware Break signal on the RS-232 line, which is associated with a reverse Telnet connection, for the current line and sessions, use the terminal telnet break-on-ip EXEC command.

terminal telnet break-on-ip
Default

Disabled

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

The hardware Break signal occurs when a Telnet Interrupt-Process (IP) command is received on that connection. The terminal telnet break-on-ip command can be used to control the translation of Telnet IP commands into X.25 Break indications.

This command is also a useful workaround in the following situations:

Some RS-232 hardware devices use a hardware Break signal for various purposes. A hardware Break signal is generated when a Telnet Break command is received.


Note This command applies only to access servers. It is not supported on standalone routers.
Example

The following example shows how to generate a Break signal on the asynchronous TTY line 4:

line tty 4
terminal telnet break-on-ip

terminal telnet refuse-negotiations

To set the current line to refuse to negotiate full-duplex, remote echo options on incoming connections for current sessions, use the terminal telnet refuse-negotiations EXEC command.

terminal telnet refuse-negotiations
Default

Disabled

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

You can set the line to allow the access server to refuse full-duplex, remote echo connection requests from the other end. This task suppresses negotiation of the Telnet Remote Echo and Suppress Go Ahead options.


Note This command applies only to access servers. It is not supported on standalone routers.
Example

The following example shows how to set an asynchronous interface to refuse full-duplex, remote echo requests:

line async 1
terminal telnet refuse-negotiations

terminal telnet speed

To allow the access server to negotiate transmission speed for the current line and session, use the terminal telnet speed EXEC command.

terminal telnet speed default-speed maximum-speed
Syntax Description
default-speed Line speed (in bps) that the access server will use if the device on the other end of the connection has not specified a speed.
maximum-speed Maximum line speed (in bps) that the device on the other end of the connection can use.
Default

9600 bps (unless otherwise set using the speed, txspeed or rxspeed line configuration commands)

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

You can match line speeds on remote systems in reverse Telnet, on host machines hooked up to an access server to access the network, or on a group of console lines hooked up to the access server, when disparate line speeds are in use at the local and remote ends of the connection. Line speed negotiation adheres to the Remote Flow Control option, defined in RFC 1080.


Note This command applies only to access servers. It is not supported on standalone routers.
Example

The following example enables the access server to negotiate a bit rate on the line using the Telnet option. If no speed is negotiated, the line will run at 2400 bps. If the remote host requests a speed of greater than 9600 bps, then 9600 bps will be used.

line async 7
terminal telnet speed 2400 9600

terminal telnet sync-on-break

To cause the access server to send a Telnet Synchronize signal when it receives a Telnet Break signal on the current line and session, use the terminal telnet sync-on-break EXEC command.

terminal telnet sync-on-break
Default

Disabled

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

You can set the line to cause a reverse Telnet line to send a Telnet Synchronize signal when it receives a Telnet BREAK signal. The TCP Synchronize signal clears the data path, but still interprets incoming commands.


Note This command applies only to access servers. It is not supported on standalone routers.
Example

The following example shows how to set an asynchronous line to cause the access server to send a Telnet synchronize signal:

line async 15
terminal telnet sync-on-break

terminal terminal-type

To specify the type of terminal connected to the current line for the current session, use the terminal terminal-type EXEC command.

terminal terminal-type terminal-type
Syntax Description
terminal-type Defines the terminal name and type and permits terminal negotiation by hosts that provide that type of service.
Default

VT100

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

Indicate the terminal type if it is different from the default of VT100. The terminal type name is used by TN3270 for display management and by Telnet and rlogin to inform the remote host of the terminal type.

Example

The following example defines the terminal on line 7 as a VT220:

Router> terminal terminal-type VT220 
Related Commands

A dagger (+) indicates that the command is documented in the "Terminal Lines and Modem Support Commands" chapter.

terminal-type +
terminal keymap-type

terminal transport preferred

To specify the preferred protocol to use for the current session when a command does not specify one, use the terminal transport preferred EXEC command.

terminal transport preferred {all | lat | mop | nasi | none | pad | rlogin | telnet}
Syntax Description
all Specifies all recognized protocols.
lat Specifies the LAT protocol.
mop Specifies the Maintenance Operation Protocol (MOP).
nasi Specifies the NetWare Asynchronous Services Interface (NASI) protocol.
none Prevents any protocol selection on the line. The router default is that any unrecognized command is a host name. If the preferred protocol is set to none, the router will not attempt any connections if the command is not recognized.
pad Specifies X.3 PAD, which is used most often to connect a server product to X.25 hosts.
rlogin Specifies UNIX rlogin.
telnet Specifies the TCP/IP Telnet protocol.
Default

lat (if lat is not supported, telnet)

Command Mode

EXEC

Usage Guidelines

The terminal transport [none | telnet] command first appeared in a release prior to Cisco IOS Release 10.0. The entire command first appeared in Cisco IOS Release 11.2.

Example

The following example shows you how to configure the console so that it does not connect when an unrecognized command is entered:

Router> terminal transport preferred none
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

transport preferred +

terminal txspeed

To set the terminal transmit speed (how fast the terminal can send information) on the current line and session, use the terminal txspeed EXEC command.

terminal txspeed bps
Syntax Description
bps Baud rate in bits per second (bps). Table 42 lists line speeds for supported access servers.
Default

9600 bps

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use Table 42 as a guide for setting the line speeds.

Example

The following example sets the current auxiliary line transmit speed to 2400 bps:

Router> terminal txspeed 2400
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

txspeed +

terminal width

To set the number of character columns on the terminal screen for the current line for a session, use the terminal width EXEC command.

terminal width characters
Syntax Description
characters Number of character columns displayed on the terminal.
Default

80 characters

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

By default, the route provides a screen display width of 80 characters. You can reset this value if it does not meet the needs of your terminal. The width specified can be learned by remote hosts.

Example

The following example sets the terminal character columns to 132:

terminal width 132
Related Command

This command is documented in the "Terminal Lines and Modem Support Commands" chapter as indicated by the dagger (+).

width +

tn3270

To begin a TN3270 session, use the tn3270 EXEC command.

tn3270 host
Syntax Description
host Name or IP address of a specific host on a network that can be reached by the router. The default terminal emulation mode allows access using a VT100 emulation.
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Unlike Telnet and LAT connections, you must enter the command tn3270 to make a connection to an IBM TN3278 host.

To terminate an active TN3270 session, enter the escape sequence (Ctrl-Shift-6 then x [Ctrl^x] by default) and enter the disconnect command at the EXEC prompt. Or log off the remote system by issuing the command specific to that system (such as exit, logout, quit, close, or disconnect).

Example

The following example establishes a terminal session with an IBM TN3270 host named finance:

Router> tn3270 finance 

tunnel

To set up a network layer connection to a router, use the tunnel user EXEC command.

tunnel host
Syntax Description
host Name or IP address of a specific host on a network that can be reached by the router.
Default

None

Command Mode

User EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

If you are a mobile user, it is often impractical to dial in to your "home" router from a remote site. The asynchronous mobility feature allows you to dial in to different routers elsewhere on the internetwork while experiencing the same server environment that you would if you were connecting directly to your home router.

This asynchronous host mobility is accomplished by packet tunneling, a technique by which raw data from the dial-in user is encapsulated and transported directly to the host site where your home router performs the actual protocol processing.

You enable asynchronous mobility by entering the tunnel command to set up a network layer connection to a specified host. From a router other than a Cisco router, however, you need to use the Telnet protocol.

After a connection is established, you receive an authentication dialog or prompt from your home router and can proceed as if you are connected directly to it. When communications are complete, the network connection can be closed and terminated from either end of the connection.

Example

The following example establishes a network layer connection with an IBM host named mktg:

Router> tunnel mktg

where

To list the open sessions, use the where EXEC command.

where
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in a release prior to Cisco IOS Release 10.0.

The where command displays all open sessions associated with the current terminal line.

The Ctrl^x, where, and resume commands are available with all supported connection protocols.

Example

The following is sample output from the where command:

sloth# where
Conn Host                 Address          Byte    Idle  Conn Name
   1 MATHOM               192.31.7.21         0       0  MATHOM
*  2 CHAFF                131.108.12.19       0       0  CHAFF 

The asterisk (*) indicates the current terminal session.

Table 43 describes significant fields shown in the display.


Table 43: Where Field Descriptions
Field Description
Conn Name or address of the remote host to which the connection is made.
Host Remote host to which the router is connected through a Telnet session.
Address IP address of the remote host.
Byte Number of unread bytes for the user to see on the connection.
Idle Interval (in minutes) since data was last sent on the line.
Conn Name Assigned name of the connection.
Related Commands

resume
show sessions

x3

To set X.3 PAD parameters, use the x3 EXEC command.

x3 parameter:value
Syntax Description
parameter:value Sets the PAD parameters. (See Table 19.)
Default Values

For outgoing connections, the X.3 parameters default to the following:

2:1, 3:2, 4:1, 7:4, 16:127, 17:21, 18:19

All other parameters default to zero, but can be changed using the /set switch keyword with either the resume command or the x3 command.

For incoming PAD connections, the software sends an X.29 SET PARAMETER packet to set only the following parameters:

2:0, 4:1, 7:21, 15:0

For a complete description of the X.3 PAD parameters, refer to the appendix "X.3 PAD Parameters."

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

You can have several PAD connections open at the same time and switch between them. You can also exit a connection and return to the user EXEC prompt at any point.

To open a new connection, first suspend the current connection by pressing the escape sequence (Ctrl-Shift-6 then x [Ctrl^x] by default) to return to the system command prompt, then open the new connection with the pad command.

You can have several concurrent sessions open and switch back and forth between them. The number of PAD sessions that can be open is defined by the session-limit command, which is described in the "Configuring Terminal Lines and Modem Support" chapter of the Access Services Configuration Guide and the "Terminal Lines and Modem Support Commands" chapter of this publication.

To switch between sessions you must escape one session and resume a previously opened session. Use the Ctrl^x, where, and resume commands, which are available with all supported connection protocols, to do this.

You can issue any of the following commands to terminate a terminal session:

exit
quit
logout

To display information about packet transmission and X.3 PAD parameter settings, use the show x25 pad command.

Example

The following example illustrates how to reset the outgoing connection default for local echo mode in the Cisco IOS software.

router> resume 3 /set 2:1

The /set switch keyword sets the X.3 parameters defined by parameter number and value, separated by a colon.

Related Command

resume

xremote

To prepare the router for manual startup and initiate an XRemote connection, use the xremote EXEC command.

xremote

This command begins the instructions that prompt you through the connection.

Default

Disabled

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

If you do not use a host computer that supports XDMCP or LAT, you must use manual session startup. Manual session startup involves the following steps:

    1 . Enable XRemote manually on the router's port.

    2 . Connect to the host computer by using a telnet, lat, or rlogin command, then log on as usual.

    3 . Set the location of the X display.

    4 . Start client applications.

    5 . Return to the EXEC prompt.

    6 . Enter the xremote command to enable XRemote manually again on the server port.


Note In manual operation, the server and X terminal remain in XRemote mode until all clients disconnect or the access server receives a reset request from the X terminal. A session might terminate
during startup because you invoked transient X clients that set some parameters (such as xset or xmodmap) and then disconnected. There must always be one session open or the connection resets.

See the Access Services Configuration Guide for more information about how to establish XRemote sessions between servers.

Examples

The following example illustrates how a successful manual XRemote session begins:

dialup> xremote
XRemote enabled; your display is dialup:2006
Start your clients and type XRemote again

The router replies with a message informing you of your X display location. Use this information to tell the XRemote host the location of your X display server. If no clients are found, you see the following message:

No X clients waiting - check that your display is darkstar:2006

The following example shows a connection from an X display terminal through a router to a host running client programs.

dialup> xremote


XRemote enabled; your display is dialup:2006
Start your clients and type XRemote again
dialup> telnet eureka
Trying EUREKA.NOWHERE.COM (252.122.1.55)... Open
SunOS UNIX (eureka)
login: deal
Password:
Last login: Fri Apr 1 17:17:46 from dialup.nowhere.com
SunOS Release (SERVER+FDDI+DBE.patched) #14: Fri Apr 8 10:37:29 PDT 1994
eureka% setenv DISPLAY dialup:2006
eureka% xterm &
[1] 15439
eureka% logout
[Connection to EUREKA closed by foreign host]
dialup> xremote
Entering XRemote

The following example shows how an XRemote connection is established for a configuration like the one shown in Figure 4. This example assumes that the administrator has set the user's display environment variable to identify the user's X display terminal.

    1 . From the PCX, MacX, or UNIX machine in Figure 4, the user connects to port 9003 on AccessServer1. If your administrator has configured a rotary number 7, the user connects to port 10007. For more information about rotary groups, refer to the Access Services Configuration Guide and this publication.

    2 . AccessServer1 connects the user to a modem.

    3 . The modem calls AccessServer2.

    4 . The user enters xremote at the AccessServer2 prompt.

    5 . The user connects to the host from AccessServer2 using the telnet command.

    6 . The user starts the X client program that will run on the host and display on the X display server (PCX, MacX, or UNIX host).

    7 . The user escapes from the host back to the AccessServer2, or logs out if clients were run in the background, and enters xremote command at the AccessServer2 prompt.


Figure 4:

XRemote Session between Servers

The following example shows how to make an XRemote connection between servers. The number 9016 in the first line of the display indicates a connection to individual line 16. If the administrator had configured a rotary connection, the user enters 10000 plus the number of the rotary instead of 9016.

space% telnet golden-road 9016
Trying 192.31.7.84 ...
Connected to golden-road.cisco.com.
Escape character is '^]'.
User Access Verification
Password:
Password OK
 --- Outbound XRemote service ---
Enter X server name or IP address: innerspace
Enter display number [0]:
 Connecting to tty16... please start up XRemote on the remote system 
atdt 13125554141
DIALING
RING
CONNECT 14400
User Access Verification
Username: deal
Password:
  Welcome to the cisco dial-up access server.
dialup> xremote
XRemote enabled; your display is dialup:2006
Start your clients and type XRemote again
dialup> telnet sparks
Trying SPARKS.NOWHERE.COM (252.122.1.55)... Open
SunOS UNIX (sparks)
login: deal
Password:
Last login: Fri Apr 1 17:17:46 from dialup.nowhere.com
SunOS Release (SERVER+FDDI+DBE.patched) #14: Fri Apr 8 10:37:29 PDT 1994
sparks% setenv DISPLAY dialup:2006
sparks% xterm &
[1] 15439
sparks% logout
[Connection to SPARKS closed by foreign host]
dialup> xremote
Entering XRemote
Related Commands

xremote lat
xremote xdm

xremote lat

To initiate a DECwindow session over a LAT connection, use the xremote lat EXEC command.

xremote lat service
Syntax Description
service Name of the desired LAT service.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

If your host computer supports DECwindows login sessions, you can use automatic session startup to make an XRemote session connection. Once the system administrator at the remote host configures support for DECwindows over LAT, use the xremote lat EXEC command to initiate the connection. After you issue this command, the following events occur:

Log on to the host. Upon completion of login, more fonts are loaded, and the remote session begins.


Note Because of heavy font usage, DECwindows applications can take longer than expected to start when using XRemote. Once the application starts, performance and access times should be as expected.

To exit XRemote sessions, you must quit all active X connections, usually with a command supported by your X client system. Usually, when you quit the last connection (when all client processes are stopped), XRemote closes and you return to the EXEC prompt. However, your X client system determines how the session closes.

Example

The following example begins connection with a LAT service named service1:

Router> xremote lat service1
Related Commands

xremote
xremote xdm

xremote xdm

To activate automatic session startup for an XRemote connection, use the xremote xdm EXEC command.

xremote xdm [hostname]
Syntax Description
hostname (Optional) Host computer name or IP address.
Default

None

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

If your host computer supports a server running XDMCP (such as the xdm program included in X11R4 or later), you can use automatic session startup to make an XRemote session connection. To do so, use the xremote xdm EXEC command.

This command sends an X Display Manager Control Protocol (XDMCP) session startup request to the host computer. If you do not specify a host name or IP address, a broadcast message is sent to all hosts. The first host to respond by starting up a session is used.

The XRemote (the host) server and X terminal stay in XRemote mode until either the display manager terminates the session or the XRemote server receives a reset request from the X terminal.

To exit XRemote sessions, you must quit all active X connections, usually with a command supported by your X client system. Usually, when you quit the last connection (all client processes are stopped), XRemote closes and you return to the EXEC prompt. However, your remote X client system determines how the session closes.

To terminate a session, disconnect from the device on the network using the command specific to that device. Then, exit from the EXEC by using the exit command.

Example

The following example starts a session with a remote host named host1:

Router> xremote xdm host1
Related Commands

xremote
xremote lat


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