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The line configuration commands described in this chapter are used to configure virtual terminal lines, the console port, and the auxiliary port.
For line configuration command descriptions, refer to the "Configuring Terminal Lines and Modem Support" chapter in the Router Products Configuration Guide.
The history line configuration command is described with other user interface commands in the "User Interface Commands" chapter of this manual. The access-class line configuration command, which applies an IP access list to a line, is described in the "Managing the System" chapter in the Router Products Configuration Guide.
The user-level EXEC commands that set terminal parameters for the duration of a session are documented in the Cisco Access Connection Guide.
To set the interval for closing the connection, use the absolute-timeout line configuration command. Use the no form of this command to restore the default.
No timeout interval is automatically set.
This command terminates the connection after the specified time period has elapsed, regardless of whether or not the connection is being used at the time of termination. You can specify an absolute timeout value for each port. The user is given 20 seconds' notice before the session is terminated. You can use this command with the logout-warning command, which notifies the user of an impending logout.
Note You can set this command and an AppleTalk Remote Access (ARA) protocol time-out for the same line; however, this command supersedes any time-outs set in ARA protocol. Additionally, ARA protocol users receive no notice of any impending termination if this interval is set.
The following example sets an interval of 60 minutes on line 5:
To define the character you type at a vacant terminal to begin a terminal session, use the activation-character line configuration command. Use the no form of this command to make any character activate a terminal.
See the "ASCII Character Set" appendix for a list of ASCII characters.
Note If you are using autoselect, let the activation character default to Return and let the exec-character-bits command default to 7. If you change these defaults, the application does not recognize the activation request.
The following example sets the activation character for the console to Delete, which is decimal 127:
To set the line for automatic baud detection, use the autobaud line configuration command. Use the no autobaud command to restore the default.
This command has no arguments or keywords.
This command pertains to the auxiliary port only.
The autobaud detection supports a range from 300 to 19200 baud. A line set for autobaud cannot be used for outgoing connections. Nor can you set autobaud capability on a line using 19200 baud when the parity bit is set because of hardware limitations.
The following example sets the auxiliary port for autobaud detection:
To configure the router to execute a command or list of commands automatically when a user connects to a particular line, use the autocommand line configuration command.
Automatic responses are not configured.
This command applies to the auxiliary port only.
The following example forces an automatic connection to a host named host21 (which could be an IP address). In addition, the UNIX UUCP application specifies TCP socket 25, and the /stream switch enables a raw TCP stream with no Telnet control sequences.
To configure automatic line disconnect, use the autohangup line configuration command. The command causes the EXEC to issue the exit command when the last connection closes.
This command has no arguments or keywords.
This command is useful for UNIX UUCP applications that automatically disconnect lines because UUCP scripts cannot issue the exit command to hang up the telephone.
The following example enables automatic line disconnect on the auxiliary port:
To configure a line to start an ARA, Point-to-Point Protocol (PPP), or SLIP session, use the autoselect line configuration command. Use the no form of this command to disable this function on a line.
Configures the router to allow an ARA session to start up automatically.
This command eliminates the need for users to enter an EXEC command to start an ARA, PPP, or SLIP session.
Note SLIP does not support authentication. For PPP and ARA protocol, you must enable authentication.
The autoselect command configures the router to identify the type of connection being requested. For example, when a user on a Macintosh running ARA selects the Connect button, the router automatically starts an ARA protocol session. If, on the other hand, the user is running SLIP or PPP and uses the autoselect ppp or autoselect slip command, the router automatically starts a PPP or SLIP session, respectively. This command is appropriate for lines used to make different types of connections.
A line that does not have autoselect configured regards an attempt to open a connection as noise. Then when the router does not respond, the user client times out.
Note After the modem connection is established, a Return is required to evoke a response such as the username prompt. You might need to update your scripts to include this requirement. Additionally, let the activation character default to Return, and the exec-character-bits default to 7. If you change these defaults, the application does not recognize the activation request.
The following example enables ARA on a line:
The following example enables PPP on a line:
The following example enables ARA on a line and allows logins from users with a modified CCL script and an unmodified script to log in:
ppp authentication chap
ppp authentication pap
arap use-tacacs
ppp use-tacacs
To display a message on terminals with an interactive EXEC, use the banner exec global configuration command. This command specifies a message to be displayed on when an EXEC process is created (line activated, or incoming connection to VTY).
Follow the command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.
The following example sets an EXEC message. The dollar sign ($) is used as a delimiting character.
banner incoming
banner motd
exec-banner
To specify a message used when you have an incoming connection to a line from a host on the network, use the banner incoming global configuration command. An incoming connection is one initiated from the network side of the router. The EXEC banner can be suppressed on certain lines using the no exec-banner line configuration command. This line should not display the EXEC or MOTD banners when an EXEC is created.
No incoming banner is displayed.
Follow the command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.
The following example sets an incoming connection message. The pound sign (#) is used as a delimiting character.
banner exec
banner motd
exec-banner
To specify a message-of-the-day (MOTD) banner, use the banner motd global configuration command.
Follow the command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.
This message-of-the-day banner is displayed to all terminals connected, and is useful for sending messages that affect all users; impending system shutdowns, for example.
The banner command without any keywords specified defaults to the banner motd command. When a new banner motd command is added to the configuration, it overwrites the existing banner command (no keyword specified). Similarly, if a banner command is added to the configuration, any exiting banner motd command is overwritten.
The following example sets a message-of-the-day banner. The pound sign (#) is used as a delimiting character.
banner exec
banner incoming
exec-banner
To create a "host failed" message that displays when a connection fails, use the busy-message global configuration command. Use the no busy-message command to disable the "host failed" message from displaying on the specified host.
The "host failed" message is not displayed.
This command applies only to Telnet connections.
Follow the busy-message command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.
Defining a "host failed" message for a host prevents all router-initiated user messages, including the initial message that indicates the connection is "Trying..." The busy-message command can be used in the autocommand command to suppress these messages.
The following example sets a message that will be displayed on the terminal whenever an attempt to connect to the host named dross fails. The pound sign (#) is used as a delimiting character.
To set the number of data bits per character that are interpreted and generated by hardware, use the databits line configuration command.
This command pertains to the auxiliary port only.
The databits line configuration 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 are supplied for compatibility with older devices and generally are not used.
The following example changes the data bits to 7 on the auxiliary port:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
terminal data-character-bits
terminal databits
To set the number of data bits per character that are interpreted and generated by software, use the data-character-bits line configuration command.
The data-character-bits line configuration command is used primarily to strip parity from X.25 connections on IGS or Cisco 3000 routers with the protocol translation software option. The data-character-bits line configuration command does not work on hardwired lines.
The following example sets the number of data bits per character for virtual terminal line 1 to 7:
To define the EXEC character width for either 7 bits or 8 bits, use the default-value exec-character-bits global configuration command.
Configuring the EXEC character width to 8 bits allows you to add graphical and international characters in banners, prompts, and so forth. 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 command help, an "unrecognized command" message appears because the system is reading all 8 bits, although the eighth bit is not needed for the help command.
The following example selects the full 8-bit ASCII character set for EXEC banners and prompts:
Two daggers () indicate that the command is documented in the Cisco Access Connnection Guide.
default-value special-character-bits
exec-character-bits
special-character-bits
terminal exec-character-bits
terminal special-character-bits
To configure the flow control default value from a 7-bit width to an 8-bit width, use the default-value special-character-bits global configuration command.
Configuring the special character width to 8 bits allows you to add graphical and international characters in banners, prompts, and so forth.
The following example selects the full 8-bit special character set:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
default-value exec-character-bits
exec-character-bits
special-character-bits
terminal exec-character-bits
terminal special-character-bits
To define a character to disconnect a session, use the disconnect-character line configuration command. This command defines the character you enter to end a terminal session. Use the no disconnect-character command to remove the disconnect character.
No disconnect character is defined.
The Break character is represented by zero; NULL cannot be represented.
To use the session disconnect character in normal communications, precede it with the escape character. See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example sets the disconnect character for virtual terminal line 4 to Escape, which is ASCII character 27:
To define a character that causes a packet to be sent, use the dispatch-character line configuration command. Use the no dispatch-character command to remove the definition of the specified dispatch character.
No dispatch character is defined.
This dispatch-character command defines a dispatch character that causes a packet to be sent even if the dispatch timer has not expired. It causes the router to attempt to buffer characters into larger-sized packets for transmission to the remote host. The router normally dispatches each character as it is typed.
This command can take multiple arguments, so you can define any number of characters as dispatch characters.
The following example specifies the Return character as the dispatch character:
To set the character dispatch timer, use the dispatch-timeout line configuration command. Use the no dispatch-timeout command to remove the timeout definition.
No dispatch timeout is defined.
The dispatch-timeout line configuration command causes the router to buffer characters into packets for transmission to the remote host. The router sends a packet a specified amount of time after the first character is put in the buffer. The router normally dispatches each character as it is entered. You can use the dispatch-timeout and dispatch-character line configuration commands together. In this case, the router dispatches a packet each time the dispatch character is entered, or after the specified dispatch timeout interval, depending on which condition is met first.
Note The router's response might appear intermittent if the timeout interval is greater than 100 milliseconds and remote echoing is used.
The following example sets the dispatch timer to 80 milliseconds:
To define a system escape character, use the escape-character line configuration command. The no escape-character command sets the escape character to Break.
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. To send the escape character to the other side, press Ctrl-^ twice.
See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example sets the escape character to Ctrl-P, which is ASCII character 16:
To allow an EXEC process on a line, use the exec line configuration command. The no exec command turns off the EXEC process for the line specified.
This command has no arguments or keywords.
By default, the router starts EXECs on all lines.
When you want to allow an outgoing connection only for a line, use the no exec command. When a user tries to Telnet to a line with the no exec command configured, the user will get no response when pressing the Return key at the login screen.
The following example illustrates how to turn off the EXEC on line 7. You might want to do this on the auxiliary port if the attached device (for example, the control port of a rack of modems) sends unsolicited data to the router. An EXEC would start if this happened, making the line unavailable.
To control whether banners are displayed or suppressed, use the exec-banner line configuration command. This command determines whether the router will display the EXEC banner or the message-of-the-day (MOTD) banner when an EXEC is created. The no exec-banner command suppresses the banner messages.
This command has no arguments or keywords.
By default, the messages defined with banner motd and banner exec commands are displayed on all lines.
The following example suppresses the banner on virtual terminal lines 0 to 4:
To configure the character widths of EXEC and configuration command characters, use the exec-character-bits line configuration command.
Setting the EXEC character width to 8 allows you to use special graphical and international characters in banners, prompts, and so forth. However, setting the EXEC character width to 8 bits can cause failures. If a user on a terminal that is sending parity enters the command help, an "unrecognized command" message appears because the system is reading all 8 bits, although the eighth bit is not needed for the help command.
Note If you are using the autoselect command, set the activation-character to the default Return and exec-character-bits to the default 7. If you change these defaults, the application does not recognize the activation request.
The following example allows full 8-bit international character sets by default, except for the console, which is an ASCII terminal. It illustrates use of the default-value exec-character-bits global configuration command and the exec-character-bits line configuration command.
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
default-value exec-character-bits
default-value special-character-bits
special-character-bits
terminal exec-character-bits
terminal special-character-bits
To set the interval that the EXEC command interpreter waits until user input is detected, use the exec-timeout line configuration command. The no exec-timeout command removes the timeout definition.
If no input is detected, the EXEC resumes the current connection, or if no connections exist, it returns the terminal to the idle state and disconnects the incoming session.
The no version of this command has the same effect as the exec-timeout 0 command.
The following example sets a time interval of 2 minutes, 30 seconds:
The following example sets a time interval of 10 seconds:
To set the method of data flow control between the terminal or other serial device and the router, use the flowcontrol line configuration command. To disable flow control, use the no form of this command.
This command pertains to the auxiliary port only.
When software flow control is set, the default stop and start characters are Ctrl-S and Ctrl-Q (XOFF and XON). You can change them with the stop-character and start-character commands.
The following example sets hardware flow control on the auxiliary port:
To define the local hold character used to pause output to the terminal screen, use the
hold-character line configuration command. The no hold-character command restores the default.
The Break character is represented by zero; NULL cannot be represented. To continue the output, type any character after the hold character. To use the hold character in normal communications, precede it with the escape character. See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example sets the hold character to Ctrl-S, which is ASCII decimal 19:
Two daggers () indicate that the command is documented in the Cisco Access Connnection Guide.
To set the terminal screen length, use the length line configuration command.
Not all commands recognize the configured screen length. For example, the show terminal command assumes a screen length of 24 lines or more. The router software uses the value of this command to determine when to pause during multiple-screen output.
The following example illustrates how to disable the screen pause function on the console terminal:
To configure a console port line, auxiliary port line, or virtual terminal lines, use the line global configuration command.
If you include one of the optional type keywords (aux, console, or vty), the line number is treated as a relative line number. If you enter the line command without an optional type keyword, the line number is treated as an absolute line number. Absolute line numbers increment consecutively and can be difficult to manage on large systems.
You can set communication parameters, specify autobaud connections, configure terminal operating parameters, and more for any of the terminal lines on the router.
The relative line number of the auxiliary port must be 0. See the modem line configuration command to set up modem support on the auxiliary port. The absolute line number of the auxiliary port is 1.
Virtual terminal lines are used to allow remote access to the router. A virtual terminal line is not associated with either the console or auxiliary port. You can address a single line or a consecutive range of lines with the line command. A line number is necessary, though, and you will receive an error message if you forget to include it.
The following example starts configuration for virtual terminal lines 0 to 4:
The following example configures the auxiliary port with a line speed of 2400 baud and enables the EXEC:
Two daggers indicate that the command is documented in the Cisco Access Connection Guide.
show line
show users all
To record the location of a serial device, use the location line configuration command. The no location command removes the description.
Locations of serial devices are not recorded.
The location command enters information about the device location and status. Use the EXEC command show users all to display the location information.
The following example identifies the location of the console:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
To enable the EXEC command lock, use the lockable global configuration command The no lockable command reinstates the default, which does not allow the terminal to be locked.
This command has no arguments or keywords.
This command allows a terminal to be temporarily inaccessible by use of a temporary password.
The following example sets the terminal to the lockable state:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
To enable password checking at login, use the login line configuration command. Use the no login command to disable password checking and allow connections without a password.
By default, virtual terminals require a password. If you do not set a password for a virtual terminal, it will respond to attempted connections by displaying an error message and closing the connection.
If you specify login without the local or tacacs option, authentication is based on the password specified with the password line configuration command.
Note This command cannot be used with Authentication, Authorization, and Accounting (AAA)/TACACS+. Use the login authentication command instead.
The following example sets the password letmein on virtual terminal line 4:
The following example illustrates how to enable the TACACS-style user ID and password-checking mechanism:
A dagger () indicates that the command is documented in another chapter.
enable password
password
username
To enable AAA/TACACS+ authentication for logins, use the login authentication line configuration command. Use the no form of the command to return to the default.
 | Caution If you use a list-name value that has not been configured with the aaa authentication login command, you will disable logins on this line. |
Login authentication uses the default set with aaa authentication login command. If no default is set, the local user database is checked. No authentication is performed on the console.
This command is a per-line command used with AAA, and specifies the name of a list of TACACS+ authentication processes to try at login. If no list is specified, the default list is used (whether or not it is specified in the command line). You create defaults and lists by using the aaa authentication login command. Note that entering the no version of login authentication has the same effect as entering the command with the default argument.
Before issuing this command, create a list of authentication processes by using the global configuration aaa authentication login command.
The following example specifies that the default AAA authentication is to be used on line 4:
The following example specifies that the AAA authentication list called MIS-access is to be used on line 7:
To define a string of characters that the router sends to a host after a successful Telnet connection, use the login-string global configuration command. This command applies only to rlogin and Telnet sessions. The no login-string command removes the login string.
Follow the command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character. To use a percent sign in the login string, precede it with another percent sign; that is, type the characters "%%." The options can be used anywhere within the message string.
In the following example, the value %5p causes a 5-second pause:
To set the amount of time that the router waits for CTS after raising DTR in response to RING, use the modem answer-timeout line configuration command. The no form of this command reverts the router to the default value.
This command applies to the auxiliary port only. It is useful for modems that take a long time to synchronize to the appropriate line speed.
The following example sets the timeout interval to 20 seconds:
To support dial-in modems that use DTR to control the off-hook status of the modem, use the modem callin line configuration command. In response to RING, the modem raises the DTR signal, which answers the modem. At the end of the session, the router lowers DTR, which disconnects the modem. The no form of this command disables this feature.
This command has no arguments or keywords.
This command applies to the auxiliary port only.
The following example causes the modem connected to the router to raise DTR in response to RING:
modem answer-timeout
modem in-out
To configure a line for reverse connections, use the modem callout line configuration command. The no form of this command disables this feature.
This command has no arguments or keywords.
This command applies to the auxiliary port only and supports ports connected to computers that are designed to be connected to modems.
The following example configures the line for reverse connections:
To configure a line to require a Clear To Send (CTS) signal, use the modem cts-required line configuration command. Use the no form of this command to disable this feature.
This command has no arguments or keywords.
This command applies to the auxiliary port only. It supports lines that either the user or the network can activate. It is useful for closing connections from a user's terminal when the terminal is turned off and for preventing disabled printers and other devices in a rotary group from being considered.
The following example configures a line to require a CTS signal:
To configure a line to leave DTR low unless the line has an active incoming connection or an EXEC process, use the modem dtr-active line configuration command. The no form of this command disables this feature.
This command has no arguments or keywords.
This command applies to the auxiliary port only. It can be useful if the line is connected to an external device (for example, a timesharing system) that needs to know whether a line is in active use. The modem dtr-active command is similar to the no modem line configuration command.
The following example illustrates how to configure the auxiliary port for low DTR:
To configure a line for both incoming and outgoing calls, use the modem in-out line configuration command. The no form of this command disables this feature.
This command has no arguments or keywords.
This command applies to the auxiliary port only.
The following example illustrates how to configure the auxiliary port for both incoming and outgoing calls:
A dagger () indicates that the command is documented in another chapter.
dialer
parity
To configure a line for a high-speed modem, use the modem ri-is-cd line configuration command. The no form of this command disables this feature.
This command has no arguments or keywords.
This command applies to the auxiliary port only. It supports modems that can automatically handle telephone line activity, such as answering the telephone after a certain number of rings.
The following example illustrates how to configure the auxiliary port for a high-speed modem:
A dagger () indicates that the command is documented in another chapter.
dialer
parity
To enable terminal notification about pending output from other connections, use the notify line configuration command. The no notify command ends notification.
This command has no arguments or keywords.
The command sets a line to inform a user who has multiple, concurrent Telnet connections when output is pending on a connection other than the current one.
The following example sets up notification of pending output from connections on virtual terminal lines 0 to 4:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
To set the padding on a specific output character, use the padding line configuration command. The no padding command removes padding for the specified output character.
Use this command if the device attached is an old terminal that requires padding after certain characters (such as ones that scrolled or moved the carriage). See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example pads a Return (ASCII decimal 13) with 25 NULL bytes:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
To define generation of a parity bit, use the parity line configuration command.
This command pertains to the auxiliary port only.
The following example changes the default of no parity to even parity:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
To specify a password on a line, use the password line configuration command. Use the no password command to remove the password.
When an EXEC is started on a line with password protection, the EXEC prompts for the password. If the user enters the correct password, the EXEC prints its normal privileged prompt. The user can try three times to enter a password before the EXEC exits and returns the terminal to the idle state.
The following example removes the password from virtual terminal lines 1 to 4:
A dagger () indicates that the command is documented in another chapter.
enable password
login (line configuration)
To save user EXEC command changes between terminal sessions, use the private line configuration command. Use the no private command to restore the default condition.
This command has no arguments or keywords.
User-set configuration options are cleared with the EXEC command exit or when the interval set with the exec-timeout line configuration command has passed.
This command ensures that the terminal parameters the user sets remain in effect between terminal sessions. This behavior is desirable for terminals in private offices.
The following example sets up virtual terminal line 1 to keep all user-supplied settings at system restarts:
A dagger () indicates that the command is documented in another chapter.
To define a line-in-use message, use the refuse-message line configuration command. Use the no refuse-message command to disable the message.
No line-in-use message is defined.
Follow the command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character. You cannot use the delimiting character within the text of the message.
When you define a message using this command, the router does the following:
In the following example, line 0 is configured with a lines-in-use message, and the user is instructed to try again later:
To define a group of lines consisting of one of more virtual terminal lines or one auxiliary port line, use the rotary line configuration command. Use the no rotary command to remove a line or group of lines from a rotary group.
Typically, rotary groups are used on devices with multiple modem connections to allow connections to the next free line in a hunt group. On routers, which can have only one modem line (the auxiliary port), rotary groups are still useful for defining groups of virtual terminal lines, or for defining a rotary group consisting of the single auxiliary port. Putting the auxiliary port in a rotary group is useful because the auxiliary port is not necessarily the same line on all hardware; by putting it in a rotary group, you don't have to track the line number.
Connections to a rotary group can take advantage of the following features:
The remote host must specify a particular TCP port on the router to connect to a rotary group with connections to an individual line. The available services are the same, but the TCP port numbers are different. Table 4-1 lists the services and port numbers for both rotary groups and individual lines.
For example, if Telnet protocols are required, the remote host connects to the TCP port numbered 3000 (decimal) plus the rotary group number. If the rotary group identifier is 13, the corresponding TCP port is 3013.
Table 4-1 Services and Port Numbers for Rotary Groups and Lines
| Services Provided | Base TCP Port for Rotaries | Base TCP Port for Individual Lines |
|---|---|---|
The following example establishes a rotary group consisting of virtual terminal lines 2 through 4 and defines a password on those lines. By using Telnet to connect to TCP port 3001, the user gets the next free line in the rotary group. The user does not have to remember the range of line numbers associated with the password.
A dagger () indicates that the command is documented in another chapter.
dialer
modem callout
modem cts-required
session-timeout
To set the terminal baud rate receive (from terminal) speed, use the rxspeed line configuration command.
Baud rate in bits per second (bps); see Table 4-2 for settings. |
This command pertains to the auxiliary port only. Set the speed to match the baud 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 will indicate if the speed you select is not supported. Use Table 4-2 as a guide for setting the line speeds.
Table 4-2 Router Line Speeds in Bits per Second
| Router Model | Baud Rates |
|---|---|
50, 75, 110, 134, 150, 200, 300, 600, 1050, 1200, 2000, 2400, 4800, 9600, 19200, 38400 |
|
75, 110, 134, 150, 300, 600, 1200, 2000, 2400, 4800, 1800, 9600, 19200, 38400 |
The following example sets the auxiliary line receive rate to 2400 bps:
To specify that a chat script start on a line any time the line is activated, use the script activation line configuration command. Use the no form of this command to disable this feature.
This command provides an asynchronous handshake to a user or device that activates the line. It can be used only on the auxiliary port of the router. The line can be activated by events like the following: a user issuing a carriage return on a vacant line, a modem on the line sensing an incoming carrier, or an asynchronous device (such as a communication server) sending data. Each time an EXEC session is started on a line, the system checks to see if a script activation command is configured on the line. If so, and the argument regexp (a regular expression) matches an existing chat script name, the matched script is run on the line.
The script activation command can mimic a login handshake of another system. For example, a system that dials into the auxiliarey port on a router and expects an IBM mainframe login handshake can be satisfied with an appropriate activation script.
This command can also send strings to asynchronous devices that are connecting or dialing into a communication server.
The script activation command functions only on physical terminal lines (tty). It does not function on virtual terminal (vty) lines.
The following example specifies that the chat script with a name that includes telebit will be activated whenever line 0 is activated:
A dagger () indicates that the command is documented in another chapter.
chat-script
dialer map modem-script system-script
dialer map modem-script system-script name
script activation
script connection
script dialer
script reset
script startup
start-chat
To specify that a chat script start on a line any time a remote network connection is made to a line, use the script connection line configuration command. Use the no form of this command to disable this feature.
This command provides modem dialing commands and commands for logging onto remote systems. The script connection command functions only on physical terminal (tty) lines. It does not function on virtual terminal (vty) lines.
This command can be used to initialize an asynchronous device sitting on a line to which a reverse network connection is made. This command can only be used on the auxiliary port of the router.
The following example specifies that the chat script with a name that includes inband will be activated whenever a remote connection to line 0 is established. The router can send a login string and password to the UNIX server when a network tunneling connection comes into line 0, the auxiliary port.
A dagger () indicates that the command is documented in another chapter
chat-script
dialer map modem-script system-script
dialer map modem-script system-script name
script activation
script dialer
script reset
script startup
start-chat
To specify that a chat script start on a line any time the specified line is reset, use the script reset line configuration command. Use the no form of this command to disable this feature.
Chat scripts provide modem dialing commands and commands for logging onto remote systems. Use this command to reset a modem attached to a line every time a call is dropped.
The script reset command functions only on physical terminal lines (tty). It does not function on virtual terminal (vty) lines. This command can only be used on the auxiliary port of the router.
This example specifies that any chat script name with the word linebackup in it will be activated any time line 0 is reset:
A dagger () indicates that the command is documented in another chapter.
chat-script
dialer map modem-script system-script
dialer map modem-script system-script name
script activation
script connection
script dialer
script startup
start-chat
To specify that a chat script start on a line any time the router is powered up, use the script startup line configuration command. Use the no form of this command to disable this feature.
Use this command to initialize asynchronous devices connected to a line when the router is powered up or reloaded. You can also use it to start up a banner other than the default banner on lines. The script startup command functions only on physical terminal (tty) lines. It does not function on virtual terminal (vty) lines. This command can only be used on the auxiliary port of the router.
The following example specifies the startup chat script as linestart:
A dagger () indicates that the command is documented in another chapter.
chat-script
dialer map modem-script system-script
dialer map modem-script system-script name
script activation
script connection
script dialer
script reset
start-chat
To configure the router to display line number information after the EXEC or incoming banner, use the service linenumber global configuration command. To disable this function, use the no form of the command.
This command has no arguments or keywords.
With the service linenumber command, you can have the router display the host name, line number, and location each time an EXEC is started or an incoming connection is made. The line number banner appears immediately after the EXEC banner or incoming banner. It is useful for tracking problems with modems because the host and line for the modem connection are listed. Modem type information can also be included.
The following example illustrates the type of line number information that can appear after the EXEC banner:
To set the maximum number of terminal sessions per line, use the session-limit line configuration command. The no session-limit command removes any specified session limit.
The default and set session limits are displayed with the show terminal EXEC command.
The following example limits the number of sessions to eight on the auxiliary port:
To set the interval for closing the connection when there is no input or output traffic, use the session-timeout line configuration command. The no session-timeout command removes the timeout definition.
The default interval is zero, indicating the router maintains the connection indefinitely.
This command sets the interval that the router waits for traffic before closing the connection to a remote computer and returning the terminal to an idle state. If the keyword output is not specified, the session timeout interval is based solely on detected input from the user. You can specify a session timeout on each port.
The following example sets an interval of 20 minutes and specifies that the timeout is subject to traffic detected from the user (input only):
To display a terminal line's parameters, use the show line EXEC command.
The following sample output from the show line command shows that line 2 is a virtual terminal with a transmit and receive rate of 9600 bps. Also shown is the modem state, terminal screen width and length, and so on.
Overruns occur when the UART serving the line receives a byte but has nowhere to put it because previous bytes have not been taken from the UART by the host CPU. The byte is lost, and the overrun count increases when theCPU next looks at UART status.
Table 4-3 describes the fields shown in this display.
Table 4-3 Show Line Field Descriptions
To configure the number of data bits per character for special characters such as software flow control characters and escape characters, use the special-character-bits line configuration command.
Setting the special character bits to 8 allows you to use twice as many special characters as with the 7-bit ASCII character set. The special characters affected by this setting are the escape, hold, stop, start, disconnect, and activation characters.
The following example allows the full 8-bit international character set for special characters on the auxiliary port:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
default-value exec-character-bits
default-value special-character-bits
exec-character-bits
terminal exec-character-bits
terminal special-character-bits
To set the terminal baud rate, use the speed line configuration command. The command sets both the transmit (to terminal) and receive (from terminal) speeds.
Baud rate in bits per second (bps); see Table 4-4 for settings. |
This command pertains to the auxiliary port only. Set the speed to match the baud 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 will indicate if the speed you select is not supported. Use the following table as a guide for setting the line speeds.
Table 4-4 Router Line Speeds in Bits per Second
| Router Model | Baud Rates |
|---|---|
50, 75, 110, 134, 150, 200, 300, 600, 1050, 1200, 2000, 2400, 4800, 9600, 19200, 38400 |
|
75, 110, 134, 150, 300, 600, 1200, 2000, 2400, 4800, 1800, 9600, 19200, 38400 |
The following example sets the auxiliary line to 2400 bps:
To set the flow control start character, use the start-character line configuration command. The command defines the character that signals the start of data transmission when software flow control is in effect. The no start-character command removes the character.
See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example changes the start character to Ctrl-B, which is ASCII decimal 2:
To manually start a chat script, use the start-chat privileged EXEC command. Use the no form of this command to stop the chat script.
This command provides modem dialing commands for a chat script that you want to apply immediately to a line. If you do not specify a line, the script runs on the current line. If the specified line is already in use, the script is not activated and an error message appears. This command can only be used on the auxiliary port of the router.
The argument regexp is used to specify the name of the modem script that is to be executed. The first script that matches the argument in this command and the dialer map command will be used. For more information about regular expressions, refer to the appendix "Regular Expressions" in this chapter.
The following example manually starts the chat script with the word telebit in its name on line 0:
A dagger () indicates that the command is documented in another chapter.
chat-script
dialer map modem-script system-script
dialer map modem-script system-script name
script activation
script connection
script dialer
script reset
script startup
To set the number of the stop bits transmitted per byte, use the stopbits line configuration command.
The following example changes the default from 2 stop bits to 1 as a performance enhancement:
To set the flow control stop character, use the stop-character line configuration command. The no stop-character command removes the character.
This command defines the character that signals the end of data transmission when software flow control is in effect. See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example changes the stop character to Ctrl-E, which is ASCII decimal 5:
To configure the router to generate a hardware Break signal upon receiving an Interrupt Process (IP) command, use the telnet break-on-ip line configuration command.
This command has no arguments or keywords.
This command causes the system to generate a hardware Break signal on the RS-232 line that is associated with a reverse Telnet connection. It is useful when a Telnet Interrupt Process (IP) command is received on that connection because it can control the translation of Telnet IP commands into X.25 Break indications. It is also a useful workaround in the following situations:
In the following example, the auxiliary port is configured with the telnet break-on-ip command. The location text indicates that this refers to the high-speed modem.
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
connect
telnet (EXEC)
terminal telnet break-on-ip
To configure a line using Telnet to refuse to negotiate full-duplex, remote echo options on incoming connections, use the telnet refuse-negotiations line configuration command.
This command has no arguments or keywords.
This command is used on reverse Telnet connections to allow the router to refuse these requests from the other end. This command suppresses negotiation of the Telnet Remote Echo and Suppress Go Ahead options.
The following example shows how to set the auxiliary port to refuse full-duplex, remote echo requests:
Two daggers () indicate that the command is documented in the Cisco Access Connnection Guide.
connect
telnet (EXEC)
terminal telnet refuse-negotiations
To allow the router to negotiate transmission speed of the line to a connected device, use the telnet speed line configuration command.
Negotiates speeds on reverse Telnet lines. You can match line speeds on remote systems in reverse Telnet, on host machines hooked up to a router to access the network, or on a group of console lines hooked up to the router, 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.
The following example allows the router to negotiate a bit rate on the line using the Telnet option. If no speed is negotiated, the line will run at 2400 bits per second. If the remote host requests a speed of greater than 9600 bps, then 9600 will be used.
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
connect
telnet (EXEC)
terminal telnet speed
To configure the router to cause an incoming connection to send a Telnet synchronize signal when it receives a Telnet Break signal, use the telnet sync-on-break line configuration command.
This command has no arguments or keywords.
Causes a reverse Telnet line to send a Telnet Synchronize signal when it receives a Telnet Break signal. This option is used very rarely to ensure the ordering of break reception with respect to data characters sent after the break.
In the following example, the auxiliary port is configured with the telnet sync-on-break command:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
connect
telnet (EXEC)
terminal telnet sync-on-break
To configure the router to send a carriage return (CR) as a CR followed by a NULL instead of a CR followed by a line feed (LF), use the telnet transparent line configuration command.
This command has no arguments or keywords.
This command is useful for coping with different interpretations of end-of-line handling in the Telnet protocol specification.
The following example causes the router, when sending a CR, to send a CR followed by a NULL character:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
connect
telnet (EXEC)
terminal telnet transparent
To specify the type of terminal connected to a line, use the terminal-type line configuration command. The command records the type of terminal connected to the line. The no terminal-type command removes any information about the type of terminal and resets the line to the default terminal emulation.
The argument terminal-name provides a record of the terminal type and allows terminal negotiation of display management by hosts that provide that type of service.
The following example defines the terminal on the console as a type VT220:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
To allow the system administrator to define which protocols to use to connect to a specific line of the access server, use the transport input line configuration command.
All protocols allowed on the line
You can specify one protocol, multiple protocols, all protocols, or no protocols. To specify multiple protocols, type the keyword for each protocol, separated by a space.
This command can be useful in distributing resources among different types of users, or making certain that only specific hosts can access a particular port. When using protocol translation, the transport input command is useful in controlling exactly which protocols can be translated to other protocols when using two-step translation.
Access lists for each individual protocol can be defined in addition to the allowances created by the transport input command. Any settings made with the transport input command override settings made with the transport preferred command.
Note Unlike defaults for other commands, the default transport input all displays when you perform show running config on TTY and AUX lines to display current settings.
The following example sets the incoming protocol to Telnet for vtys 0 to 32:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
terminal transport input
transport output
transport preferred
To determine the protocols that can be used for outgoing connections from a line, use the transport output line configuration command.
You can specify one protocol, multiple protocols, all protocols, or no protocols. To specify multiple protocols, type the keyword for each protocol, separated by a space.
Any settings made with the transport output command override settings made with the transport preferred command.
The following example prevents any protocol selection:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
terminal transport output
transport input
transport preferred
To specify the transport protocol the router uses if the user does not specify one when initiating a connection, use the transport preferred line configuration command.
Specify transport preferred none to prevent errant connection attempts.
The following example sets the preferred protocol to Telnet on virtual terminal line 1:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
terminal transport preferred
transport input
transport outputt
To set the terminal transmit baud rate (to terminal), use the txspeed line configuration command.
Baud rate in bits per second (bps); see Table 4-5 for settings. |
Set the speed to match the baud 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 will indicate if the speed you select is not supported. Use Table 4-5 as a guide for setting the line speeds.
Table 4-5 Router Line Speeds in Bits per Second
| Router Model | Baud Rates |
|---|---|
50, 75, 110, 134, 150, 200, 300, 600, 1050, 1200, 2000, 2400, 4800, 9600, 19200, 38400 |
|
75, 110, 134, 150, 300, 600, 1200, 2000, 2400, 4800, 1800, 9600, 19200, 38400 |
The following example sets the auxiliary line transmit speed to 2400 bps:
To display an idle terminal message, use the vacant-message line configuration command. The command enables the banner to be displayed on the screen of an idle terminal. The vacant-message command without any arguments restores the default message. The no vacant-message command removes the default vacant message or any other vacant message that may have been set.
The format of the default vacant message is as follows:
This message is generated by the system.
Follow the command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.
The following example turns on the system banner and displays this message:
To set the terminal screen width, use the width line configuration command. This command sets the number of character columns displayed on the attached terminal.
The rlogin protocol uses the characters argument to set up terminal parameters on a remote host.
Some hosts can learn the values for both length and width specified with the line and width commands.
The following example changes the character columns to 132 for the console terminal:
Two daggers () indicate that the command is documented in the Cisco Access Connection Guide.
Posted: Wed Jul 2 23:39:33 PDT 2003
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