|
|
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 of the Router Products Configuration Guide.
To set the activation character, use the activation-character line configuration command. This command defines the character you type at a vacant terminal to begin a terminal session. Use the no activation-character command to make any character to activate a terminal.
activation-character ASCII-number| ASCII-number | ASCII decimal representation of the activation character. |
Return (ASCII decimal 13)
Line configuration
See Appendix D, "ASCII Character Set," for a list of ASCII characters.
The following example sets the activation character for the console to Delete, which is ASCII decimal 127.
line console
activation-character 127
To set the line for automatic baud detection, use the autobaud line configuration command. Use the no autobaud command to restore the default.
autobaudThis command has no arguments or keywords.
No autobaud detection
Line configuration
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:
line aux 0
autobaud
To configure the router to automatically execute a command or list of commands when a user connects to a particular line, use the autocommand line configuration command.
autocommand command| command | Any appropriate EXEC command, including the host name and any switches that occur with the EXEC command. |
None
Line configuration
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.
line vty 4
autocommand connect host21 uucp /stream
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.
autohangupThis command has no arguments or keywords.
Disabled
Line configuration
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:
line aux 0
autohangup
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).
banner exec d message d| d | Delimiting character of your choice--a pound sign (#), for example. You cannot use the delimiting character in the banner message. |
| message | Message text. |
None
Global configuration
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 exec $
Session activated. Enter commands at the prompt.
$
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.
banner incoming d message d| d | Delimiting character of your choice--a pound sign (#), for example. You cannot use the delimiting character in the banner message. |
| message | Message text. |
None
Global configuration
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 incoming #
Welcome to Rhesus.
#
banner exec
banner motd
exec-banner
To specify a message-of-the-day (MOTD) banner, use the banner motd global configuration command.
banner motd d message d| d | Delimiting character of your choice--a pound sign (#), for example. You cannot use the delimiting character in the banner message. |
| message | Message text. |
None
Global configuration
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 motd #
Building power will be off from 7:00 AM until 9:00 AM this coming Tuesday.
#
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.
busy-message hostname d message d| hostname | Name of the host that cannot be reached. |
| d | Delimiting character of your choice--a pound sign (#), for example. You cannot use the delimiting character in the message. |
| message | Message text. |
None
Global configuration
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.
busy-message dross #
Cannot connect to host. Contact the computer center.
#
To set the number of data bits per character that are interpreted and generated by software, use the data-character-bits line configuration command.
data-character-bits {7 | 8}| 7 | Seven data bits per character. |
| 8 | Eight data bits per character. |
8 data bits per character
Line configuration
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:
line vty 1
data-character-bits 7
To set the number of data bits per character that are interpreted and generated by hardware, use the databits line configuration command.
databits {5 | 6 | 7 | 8}| 5 | Five data bits per character. |
| 6 | Six data bits per character. |
| 7 | Seven data bits per character. |
| 8 | Eight data bits per character. |
8 data bits per character
Line configuration
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:
line aux 0
databits 7
A dagger (+) indicates that the command is documented in another chapter.
terminal data-character-bits +
terminal databits +
To define the EXEC character width for either 7 bits or 8 bits, use the default-value exec-character-bits global configuration command.
default-value exec-character-bits {7 | 8}| 7 | Selects the 7-bit ASCII character set. |
| 8 | Selects the full 8-bit ASCII character set. |
7-bit ASCII character set
Global configuration
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:
default-value exec-character-bits 8
A dagger (+) indicates that the command is documented in another chapter.
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.
default-value special-character-bits {7 | 8}| 7 | Selects the 7-bit character set. |
| 8 | Selects the full 8-bit character set. |
7-bit character set
Global configuration
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:
default-value special-character-bits 8
A dagger (+) indicates that the command is documented in another chapter.
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.
disconnect-character ASCII-number| ASCII-number | ASCII decimal representation of the session disconnect character. |
None
Line configuration
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 Appendix D, "ASCII Character Set," 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:
line vty 4
disconnect-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.
dispatch-character ASCII-number1 [ASCII-number2 . . . ASCII-number]| ASCII-number | ASCII decimal representation of the character, such as Return (ASCII decimal 13) for line-at-a-time transmissions. |
None
Line configuration
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:
line vty 4
dispatch-character 13
dispatch-timeout
To set the character dispatch timer, use the dispatch-timeout line configuration command. Use the no dispatch-timeout command to remove the timeout definition.
dispatch-timeout milliseconds| milliseconds | Integer that specifies the number of milliseconds the router waits after putting the first character into a packet buffer before sending the packet. During this interval, more characters may be added to the packet, which increases the processing efficiency of the remote host. |
None
Line configuration
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.
The following example sets the dispatch timer to 80 milliseconds:
line vty 0 4
dispatch-timeout 80
dispatch-character
To enable enhanced editing mode for a particular line, use the editing line configuration command. To disable the enhanced editing mode, use the no form of this command.
editingThis command has no arguments or keywords.
Enabled
Line configuration
Table 1-1 provides a description of the keys used to enter and edit commands. Ctrl indicates the Control key. It must be pressed simultaneously with its associated letter key. Esc indicates the Escape key. It must be pressed first, followed by its associated letter key. Keys are not case sensitive.
| Keys | Function |
|---|---|
| Tab | Completes a partial command name entry. When you enter a unique set of characters and press the Tab key, the system completes the command name. If you enter a set of characters that could indicate more than one command, the system beeps to indicate an error. Enter a question mark (?) immediately following the partial command (no space). The system provides a list of commands that begin with that string. |
| Delete or Backspace | Erases the character to the left of the cursor. |
| Return | At the command line, pressing the Return key performs the function of processing a command. At the "---More---" prompt on a terminal screen, pressing the Return key scrolls down a line. |
| Space Bar | Allows you to see more output on the terminal screen. Press the space bar when you see the line "---More---" on the screen to display the next screen. |
| Left Arrow1 | Moves the cursor one character to the left. When you enter a command that extends beyond a single line, you can press the Left Arrow key repeatedly to scroll back toward the system prompt and verify the beginning of the command entry. |
| Right Arrow1 | Moves the cursor one character to the right. |
| Up Arrow1 or Ctrl-P | Recalls commands in the history buffer, beginning with the most recent command. Repeat the key sequence to recall successively older commands. |
| Down Arrow1 or Ctrl-N | Return to more recent commands in the history buffer after recalling commands with the Up Arrow or Ctrl-P. Repeat the key sequence to recall successively more recent commands. |
| Ctrl-A | Moves the cursor to the beginning of the line. |
| Ctrl-B | Moves the cursor back one character. |
| Ctrl-D | Deletes the character at the cursor. |
| Ctrl-E | Moves the cursor to the end of the command line. |
| Ctrl-F | Moves the cursor forward one character. |
| Ctrl-K | Deletes all characters from the cursor to the end of the command line. |
| Ctrl-L and Ctrl-R | Redisplays the system prompt and command line. |
| Ctrl-T | Transposes the character to the left of the cursor with the character located at the cursor. |
| Ctrl-U and Ctrl-X | Deletes all characters from the cursor back to the beginning of the command line. |
| Ctrl-V and Esc Q | Inserts a code to indicate to the system that the keystroke immediately following should be treated as a command entry, not as an editing key. |
| Ctrl-W | Deletes the word to the left of the cursor. |
| Ctrl-Y | Recalls the most recent entry in the delete buffer. The delete buffer contains the last ten items you have deleted or cut. Ctrl-Y can be used in conjunction with Esc Y. |
| Ctrl-Z | Ends configuration mode and returns you to the EXEC prompt. |
| Esc B | Moves the cursor back one word. |
| Esc C | Capitalizes the word at the cursor. |
| Esc D | Deletes from the cursor to the end of the word. |
| Esc F | Moves the cursor forward one word. |
| Esc L | Changes the word at the cursor to lowercase. |
| Esc U | Capitalizes from the cursor to the end of the word. |
| Esc Y | Recalls the next buffer entry. The buffer contains the last ten items you have deleted. Press Ctrl-Y first to recall the most recent entry. Then press Esc Y up to nine times to recall the remaining entries in the buffer. If you bypass an entry, continue to press Esc Y to cycle back to it. |
Table 1-2 lists the editing keys and functions of the earlier software release.
| Key | Function |
|---|---|
| Delete or Backspace | Erases the character to the left of the cursor. |
| Ctrl-W | Erases a word. |
| Ctrl-U | Erases a line. |
| Ctrl-R | Redisplays a line. |
| Ctrl-Z | Ends configuration mode and returns to the EXEC prompt. |
| Return | Executes single-line commands. |
In the following example, enhanced editing mode is disabled on virtual terminal line 3:
line vty 3
no editing
A dagger (+) indicates that the command is documented in another chapter.
terminal editing +
To define a system escape character, use the escape-character line configuration command. The no escape-character command sets the escape character to Break.
escape-character ASCII-number| ASCII-number | Either the ASCII decimal representation of the character or a control sequence (Ctrl-E, for example). |
Ctrl-^
Line configuration
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 Appendix D, "ASCII Character Set," for a list of ASCII characters.
The following example sets the escape character to Ctrl-P, which is ASCII character 16:
line console
escape-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.
execThis command has no arguments or keywords.
By default, the router starts EXECs on all lines.
Line configuration
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.
line 7
no exec
To control whether banners are displayed or suppressed, use the exec-banner line configuration command. This command determines whether or not 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.
exec-bannerThis command has no arguments or keywords.
By default, the messages defined with banner motd and banner exec commands are displayed on all lines.
Line configuration
The following example suppresses the banner on virtual terminal lines 0 to 4:
line aux 0
no exec-banner
banner exec
banner motd
To configure the character widths of EXEC and configuration command characters, use the exec-character-bits line configuration command.
exec-character-bits {7 | 8}| 7 | Selects the 7-bit character set. |
| 8 | Selects the full 8-bit character set for use of international and graphical characters in banner messages, prompts, and so forth. |
7-bit ASCII character set
Line configuration
Configuring 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.
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.
default-value exec-character-bits 8
line 0
exec-character-bits 7
A dagger (+) indicates that the command is documented in another chapter.
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. It is the same as entering exec-timeout 0.
| minutes | Integer that specifies the number of minutes. |
| seconds | (Optional.) Additional time intervals in seconds. An interval of zero specifies no time-outs. |
10 minutes
Line configuration
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 following example sets a time interval of 2 minutes, 30 seconds:
line console
exec-timeout 2 30
The following example sets a time interval of 10 seconds:
line console
exec-timeout 0 10
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.
flowcontrol {none | software [in | out] | hardware [in | out]}| none | Turns off flow control. |
| software | Sets software flow control. An optional keyword 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 are assumed. |
| hardware | Sets hardware flow control. An optional keyword 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 are assumed. For more information about hardware flow control, see the hardware installation and maintenance manual for your router. |
no flowcontrol
Line configuration
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:
line aux 0
flowcontrol hardware
start-character
stop-character
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.
| ASCII-number | Either the ASCII decimal representation of the hold character or a control sequence (for example, Ctrl-P). |
None
Line configuration
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 Appendix D, "ASCII Character Set," for a list of ASCII characters.
The following example sets the hold character to Ctrl-S, which is ASCII decimal 19:
line aux 0
hold-character 19
A dagger (+) indicates that the command is documented in another chapter.
terminal hold-character +
To set the terminal screen length, use the length line configuration command.
length screen-length| screen-length | Number of lines on the screen. A value of zero disables pausing between screens of output. |
24 lines
Line configuration
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:
line console
terminal-type VT220
length 0
To configure a console port line, auxiliary port line, or virtual terminal lines, use the line global configuration command.
line [aux | console | vty] line-number [ending-line-number]| aux | (Optional.) Enables the auxiliary RS-232 DTE port. Must be addressed as relative line 0. The auxiliary port can be used for modem support and asynchronous connections. |
| console | (Optional.) Specifies the console terminal line. The console port is DCE. |
| vty | (Optional.) Specifies a virtual terminal for remote console access. |
| line-number | Specifies the relative number of the terminal line (or the first line in a contiguous group) you want to configure when the line type is specified. Numbering begins with zero. |
| ending-line-number | (Optional.) Specifies the relative number of the last line in a contiguous group you want to configure. If you omit the keyword, then line-number and ending-line-number are absolute rather than relative line numbers. |
None
Global configuration
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:
line vty 0 4
The following example configures the auxiliary port with a line speed of 2400 baud and enables the EXEC:
line aux 0
exec
speed 2400
A dagger (+) indicates that the command is documented in another chapter.
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.
location text| text | Location description. |
None
Line configuration
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:
line console
location Building 3, Basement
A dagger (+) indicates that the command is documented in another chapter.
show users all +
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.
lockableThis command has no arguments or keywords.
Not lockable
Global configuration
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:
lockable
A dagger (+) indicates that the command is documented in another chapter.
lock +
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.
login [local | tacacs]| local | (Optional.) Selects local password checking. Authentication is based on the username specified with the username global configuration command. |
| tacacs | (Optional.) Selects the TACACS-style user ID and password-checking mechanism. |
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.
Line configuration
If you specify login without the local or tacacs option, authentication is based on the password specified with the password line configuration command.
The following example sets the password letmein on virtual terminal line 4:
line vty 4
password letmein
login
The following example illustrates how to enable the TACACS-style user ID and password-checking mechanism:
line 0
password mypassword
login tacacs
A dagger (+) indicates that the command is documented in another chapter.
enable password +
password
username +
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.
login-string hostname d message [%secp] [%secw] [%b] dNone
Global configuration
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:
login-string office #ATDT 555-1234
%5p hello
#
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.
modem answer-timeout seconds| seconds | Specifies the timeout interval in seconds. |
15 seconds
Line configuration
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:
line aux 0
modem answer-timeout 20
modem callin
modem in-out
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.
modem callinThis command has no arguments or keywords.
no modem control
Line configuration
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:
line aux 0
modem callin
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.
modem calloutThis command has no arguments or keywords.
no modem control
Line configuration
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:
line aux 0
modem callout
modem in-out
rotary
To specify a default modem chat script, use the modem chat-script line configuration command. Use the no form of this command to disable this feature.
modem chat-script regular-expression| regular-expression | Specifies the set of modem scripts that might be executed. The first script that matches the argument regular-expression will be used. |
Line configuration
This command applies to the auxiliary port only. Scripts are used to give modem dialing commands and commands to log onto remote systems.
The following example specifies the default modem chat script as slipdial:
line aux 0
modem chat-script slipdial
A dagger (+) indicates that the command is documented in another chapter.
chat-script +
dialer
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.
modem cts-requiredThis command has no arguments or keywords.
no modem control
Line configuration
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:
line aux 0
modem cts-required
rotary
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.
modem dtr-activeThis command has no arguments or keywords.
no modem control
Line configuration
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:
line aux 0
modem dtr-active
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.
modem in-outThis command has no arguments or keywords.
no modem control
Line configuration
This command applies to the auxiliary port only.
The following example illustrates how to configure the auxiliary port for both incoming and outgoing calls:
line aux 0
modem in-out
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.
modem ri-is-cdThis command has no arguments or keywords.
no modem control
Line configuration
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:
line aux 0
modem ri-is-cd
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.
notifyThis command has no arguments or keywords.
Disabled
Line configuration
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:
line vty 0 4
notify
A dagger (+) indicates that the command is documented in another chapter.
terminal notify +
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.
padding ASCII-number count| ASCII-number | ASCII decimal representation of the character. |
| count | Number of NULL bytes sent after that character, up to 255 padding characters in length. |
None
Line configuration
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 Appendix D, "ASCII Character Set," for a list of ASCII characters.
The following example pads a Return (ASCII decimal 13) with 25 NULL bytes:
line console
padding 13 25
A dagger (+) indicates that the command is documented in another chapter.
terminal padding +
To define generation of a parity bit, use the parity line configuration command.
parity {none | even | odd | space | mark}| none | No parity. |
| even | Even parity. |
| odd | Odd parity. |
| space | Space parity. |
| mark | Mark parity. |
no parity
Line configuration
This command pertains to the auxiliary port only.
The following example changes the default of no parity to even parity:
line aux 0
parity even
A dagger (+) indicates that the command is documented in another chapter.
terminal parity +
To specify a password on a line, use the password line configuration command. Use the no password command to remove the password.
password password| password | Case-sensitive character string that specifies the line password. The first character cannot be a number. The string can contain any alphanumeric characters, including spaces, up to 80 characters. You cannot specify the password in the format number-space-anything. The space after the number causes problems. For example, hello 21 is a legal password, but 21 hello is not. The password checking is case sensitive. For example, the password Secret is different than the password secret. |
None
Line configuration
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:
line vty 1 4
no password
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.
privateThis command has no arguments or keywords.
By default, 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.
Line configuration
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:
line vty 1
private
exec-timeout
exit
To define a line-in-use message, use the refuse-message line configuration command. Use the no refuse-message command to disable the message.
refuse-message d message d| d | Delimiting character of your choice--a pound sign (#) for example. You cannot use the delimiting character in the message. |
| message | Message text. |
None
Line configuration
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:
line aux 0
refuse-message /The dial-out modem is currently in use.
Please 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.
rotary group| group | Integer between 1 and 100 that you choose to identify the rotary group. |
None
Line configuration
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 1-3 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.
| Services Provided | Base TCP Port for Rotaries | Base TCP Port for Individual Lines |
|---|---|---|
| Telnet Protocol | 3000 | 2000 |
| Raw TCP protocol (no Telnet protocol) | 5000 | 4000 |
| Telnet protocol, binary mode | 7000 | 6000 |
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.
line vty 2 4
rotary 1
password letmein
login
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.
rxspeed bps| bps | Baud rate in bits per second (bps); see Table 1-4 for settings. |
9600 bps
Line configuration
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 1-4 as a guide for setting the line speeds.
| Router Model | Baud Rates |
|---|---|
| Cisco 7000, AGS, CGS, MGS | 50, 75, 110, 134, 150, 200, 300, 600, 1050, 1200, 2000, 2400, 4800, 9600, 19200, 38400 |
| IGS, Cisco 2000, Cisco 3000, Cisco 4000 | 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:
line aux 0
rxspeed 2400
speed
txspeed
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.
service linenumberThis command has no arguments or keywords.
Disabled
Global configuration
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:
user1@location1%telnet router2 2001
Trying 131.109.44.37
Connected to user1-gw.cisco.com
Escape character is '^]'.
router1 line 1 virtual terminal 0
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.
session-limit session-number| session-number | Specifies the maximum number of sessions. |
The default and set session limits are displayed with the show terminal EXEC command.
Line configuration
The following example limits the number of sessions to eight on the auxiliary port:
line aux 0
session-limit 8
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.
session-timeout minutes [output]| minutes | Specifies the time interval in minutes. |
| output | (Optional.) Specifies that when traffic is sent to an asynchronous line from the router (within the specified interval), the connection is retained. |
The default interval is zero, indicating the router maintains the connection indefinitely.
Line configuration
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):
line aux 0
session-timeout 20
The following example sets an interval of 10 minutes, subject to traffic on the line in either direction:
line aux 0
session-timeout 10 output
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.
special-character-bits {7 | 8}| 7 | Selects the 7-bit ASCII character set. |
| 8 | Selects the full 8-bit character set for special characters. |
7-bit ASCII character set
Line configuration
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:
line aux 0
special-character-bits 8
A dagger (+) indicates that the command is documented in another chapter.
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.
speed bps| bps | Baud rate in bits per second (bps); see Table 1-5 for settings. |
9600 bps
Line configuration
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.
| Router Model | Baud Rates |
|---|---|
| Cisco 7000, AGS, CGS, MGS | 50, 75, 110, 134, 150, 200, 300, 600, 1050, 1200, 2000, 2400, 4800, 9600, 19200, 38400 |
| IGS, Cisco 2000, Cisco 3000, Cisco 4000 | 75, 110, 134, 150, 300, 600, 1200, 2000, 2400, 4800, 1800, 9600, 19200, 38400 |
The following example sets the auxiliary line to 2400 bps:
line aux 0
speed 2400
rxspeed
txspeed
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.
start-character ASCII-number| ASCII-number | ASCII decimal representation of the start character |
ASCII decimal 17
Line configuration
See Appendix D, "ASCII Character Set," for a list of ASCII characters.
The following example changes the start character to Ctrl-B, which is ASCII decimal 2:
line aux 0
start-character 2
flowcontrol
stop-character
To set the flow control stop character, use the stop-character line configuration command. The no stop-character command removes the character.
stop-character ASCII-number| ASCII-number | ASCII decimal representation of the stop character. |
ASCII decimal 19
Line configuration
This command defines the character that signals the end of data transmission when software flow control is in effect. See Appendix D, "ASCII Character Set," for a list of ASCII characters.
The following example changes the stop character to Ctrl-E, which is ASCII decimal 5:
line aux 0
stop-character 5
flowcontrol
start-character
To set the number of the stop bits transmitted per byte, use the stopbits line configuration command.
stopbits {1 | 1.5 | 2}| 1 | One stop bit. |
| 1.5 | One and one-half stop bits. |
| 2 | Two stop bits. |
2 stop bits
Line configuration
The following example changes the default from 2 stop bits to 1 as a performance enhancement:
line aux 0
stopbits 1
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.
telnet break-on-ipThis command has no arguments or keywords.
None
Line configuration
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.
line aux 0
location high-speed modem
telnet break-on-ip
A dagger (+) indicates that the command is documented in another chapter.
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.
telnet refuse-negotiationsThis command has no arguments or keywords.
None
Line configuration
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:
line aux 0
telnet refuse-negotiations
A dagger (+) indicates that the command is documented in another chapter.
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.
telnet speed default-speed maximum-speed| default-speed | Line speed (in bps) that the router will use if the device on the other end of the connection has not specified a speed. |
| maximum-speed | Maximum speed (in bps) that the device on the port will use. |
None
Line configuration
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.
line aux 0
telnet speed 2400 9600
A dagger (+) indicates that the command is documented in another chapter.
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.
telnet sync-on-breakThis command has no arguments or keywords.
None
Line configuration
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:
line aux 0
telnet sync-on-break
A dagger (+) indicates that the command is documented in another chapter.
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.
telnet transparentThis command has no arguments or keywords.
None
Line configuration
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:
line aux 0
telnet transparent
A dagger (+) indicates that the command is documented in another chapter.
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.
terminal-type terminal-name| terminal-name | Terminal name and type. |
VT100
Line configuration
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:
line console
terminal-type VT220
A dagger (+) indicates that the command is documented in another chapter.
terminal terminal-type +
To allow the system administrator to define which protocols to use to connect to a specific line of the router, use the transport input line configuration command.
transport input {mop telnet | none}| mop | Selects the MOP protocol. |
| telnet | Specifies all types of incoming TCP/IP connections. |
| none | Prevents any protocol selection on the line. This makes the port unusable by incoming connections. |
Both protocols allowed on the line
Line configuration
You can specify one protocol, multiple protocols, or else specify none.
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 also useful in controlling exactly which protocols can be translated to other protocols when using two-step translation.
Access lists for each individual protocol may be defined in addition to the allowances created by the transport input command.
The following example sets the preferred incoming protocol to Telnet:
line vty 0 32
transport input telnet
A dagger (+) indicates that the command is documented in another chapter.
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.
transport output {telnet | none}| telnet | Selects the TCP/IP Telnet protocol. It allows a user at one site to establish a TCP connection to a login server at another site. |
| none | Prevents any protocol selection on the line. The system normally assumes that any unrecognized command is a host name. If the protocol is set to none, the system no longer makes that assumption. No connection will be attempted if the command is not recognized. |
Telnet
Line configuration
The following example illustrates how to protect inbound connections:
!
! On a router, don't allow any inbound connections to the
! ports that are actual terminals. This prevents trojan horse programs
! from attaching to the port and deriving passwords.
!
line 1 20
location Undergrad terminal room
transport input none
!
A dagger (+) indicates that the command is documented in another chapter.
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.
transport preferred {telnet | none}| telnet | Selects the TCP/IP Telnet protocol. It allows a user at one site to establish a TCP connection to a login server at another site. |
| none | Prevents any protocol selection on the line. The system normally assumes that any unrecognized command is a host name. If the protocol is set to none, the system no longer makes that assumption. No connection will be attempted if the command is not recognized. |
Telnet
Line configuration
Specify transport preferred none to prevent errant connection attempts.
The following example sets the preferred protocol to Telnet on virtual terminal line 1:
!
line vty 1
transport preferred telnet
!
A dagger (+) indicates that the command is documented in another chapter.
terminal transport preferred +
transport input
transport output
To set the terminal transmit baud rate (to terminal), use the txspeed line configuration command.
txspeed bps| bps | Baud rate in bits per second (bps); see Table 1-6 for settings. |
9600 bps
Line configuration
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.
| Router Model | Baud Rates |
|---|---|
| Cisco 7000, AGS, CGS, MGS | 50, 75, 110, 134, 150, 200, 300, 600, 1050, 1200, 2000, 2400, 4800, 9600, 19200, 38400 |
| IGS, Cisco 2000, Cisco 3000, Cisco 4000 | 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:
line aux 0
txspeed 2400
rxspeed
speed
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.
vacant-message [d message d]| d | (Optional.) A delimiting character of your choice--a pound sign (#), for example. You cannot use the delimiting character in the banner message. |
| message | (Optional.) Vacant terminal message. |
The format of the default vacant message is as follows:
<blank lines>
hostname tty# is now available
<blank lines>
Press RETURN to get started.
This message is generated by the system.
Line configuration
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:
line 0
vacant-message #
Welcome to Cisco Systems, Inc.
Press Return to get started.
#
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.
width characters| characters | Integer that specifies the number of character columns displayed on the terminal. |
80 character columns
Line configuration
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:
line console
location console terminal
width 132
A dagger (+) indicates that the command is documented in another chapter.
terminal width +
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