|
|
This chapter describes the commands used to access user and privileged EXEC command modes. It provides a description of the help command and features, lists the command editing keys and functions, and details the command history feature.
This chapter also includes the EXEC commands that can be used to set various terminal parameters on a temporary basis (for the duration of a session). It includes the Telnet commands you can use to make a connection from a terminal to a remote router in order to configure the router. The commands to actually configure these parameters on a more permanent basis are provided in the "Terminal Line and Modem Support Commands" chapter in the Router Products Command Reference publication.
You need enter only enough characters of a command to uniquely identify the command, thereby abbreviating the command syntax you type.
For user interface task information and examples, refer to the "Understanding the User Interface" chapter of the Router Products Configuration Guide.
Use the clear line EXEC command to return a terminal line to idle state.
clear line line-number| line-number | Absolute line number |
None
EXEC
Use this command to log out of a specific session running on another line. If the line uses a modem, the modem will be disconnected.
In the following example, line 3 is reset:
clear line 3
To make a Telnet connection, enter the connect EXEC command at the system prompt.
connect host [port] [keyword]| host | Host name or an Internet address. |
| port | (Optional) Decimal TCP port number; the default is the Telnet server port (decimal 23) on the host. |
| keyword | (Optional) Keyword that can be set with the connection; see Table 2-1 for a list of keywords. |
| Keyword | Description |
|---|---|
| /route: path | Specifies loose source routing. The argument path is a list of host names or Internet addresses that specifies network nodes, ending with the final destination. |
| /line | Enables Telnet line mode. In this mode, the router does not send any data to the host until you press Return. You can edit the line using the standard router command editing characters (Backspace, Delete, Ctrl-U, Ctrl-W). The /line keyword is a local option; the remote server is not notified of the mode change. |
| /debug | Enables Telnet debugging mode. |
| /stream | Turns on stream processing, which enables a raw TCP stream with no Telnet control sequences. A stream connection does not process Telnet options and may be appropriate for connections to ports running UUCP and other non-Telnet protocols. |
EXEC
You are not required to enter the command connect to establish a Telnet connection. If you prefer, you can just enter the host name. Omit the command word connect if the host name you want to use is not the same as a router command word. See the transport preferred command to disable this capability.
The router assigns a logical name to each connection; several commands use these names to identify connections. The logical name is the same as the host name, unless that name is already in use or you change the connection name with the EXEC command name-connection. If the name is already in use, the router assigns a null name to the connection.
The following example routes packets from the source system to kl.sri.com, then to 10.1.0.11, and finally to mathom:
connect mathom /route:kl.sri.com 10.1.0.11 mathom
The following example connects to a host with logical name mathom:connect mathom
A dagger (+) indicates that the command is documented in another chapter.
name-connection
resume
telnet
transport preferred none +
To exit privileged EXEC mode and return to user EXEC mode, enter the disable EXEC command.
disableThis command has no arguments or keywords.
EXEC
In the following example, entering the disable command causes the system to exit privileged EXEC mode and return to user EXEC mode as indicated by the angle bracket (>):
Router# disable
Router>
enable
To close a Telnet connection, enter the disconnect EXEC command at the system prompt.
disconnect [connection]| connection | (Optional) Connection name or number; the default is the current connection. |
EXEC
Do not use the disconnect command to end a terminal session. Instead, log off the host, which allows the host to initiate the disconnect, then use exit to close the session. If you cannot log off the host using exit, use the disconnect command.
The following example illustrates how to disconnect a specific session. First use the where command to list the current sessions:
Router> where
Conn Host Address Byte Idle Conn Name
* 1 Eng1 192.31.6.22 0 0 my host
2 Term2 192.33.6.21 0 0 Term2
Router> disconnect my host
Closing connection to Eng1 [confirm]
exit
logout
To enter privileged EXEC mode, use the enable EXEC command.
enableThis command has no arguments or keywords.
EXEC
Because many of the privileged commands set operating parameters, privileged access should be password-protected to prevent unauthorized use. If the system administrator has set a password with the enable password global configuration command, you are prompted to enter it before being allowed access to privileged EXEC mode. The password is case sensitive.
In the following example, the user enters the enable command and is prompted to enter a password. The password is not displayed on the screen. After entering the password, the system enters privileged command mode as indicated by the # symbol.
Router> enable
Password:
Router#
A dagger (+) indicates that the command is documented in another chapter.
disable
enable password +
To exit configuration mode, use the end global configuration command.
endThis command has no arguments or keywords.
Global configuration
You can also press Ctrl-Z to exit configuration mode.
In the following example, the router name is changed to alibaba using the hostname global configuration command. Entering the end command causes the system to exit configuration mode and return to EXEC mode.
Router(config)# hostname alibaba
alibaba(config)# end
alibaba#
To exit any command mode or close an active terminal session and terminate the EXEC, use the exit command at the system prompt.
exitThis command has no arguments or keywords.
Available in all command modes
When you enter the exit command at the EXEC levels, the EXEC mode is ended. Use the exit command at the configuration level to return to privileged EXEC mode. Use the exit command in interface, line, router, ipx-router, and route-map command modes to return to global configuration mode. Use the exit command in subinterface configuration mode to return to interface configuration mode. You can also press Ctrl-Z from any configuration mode to return to privileged EXEC mode.
In the following example, the user exits subinterface configuration mode to return to interface configuration mode:
Router(config-subif)# exit
Router(config-if)#
The following example shows how to exit an active session.
Router> exit
disconnect
logout
To get help for the full set of user-level commands, use the full-help command.
full-helpThis command has no arguments or keywords.
Disabled
Available in all command modes.
The full-help command enables (or disables) an unprivileged user to see all of the help messages available. It is used with the show ? command.
The following example is output for show ? with full-help disabled:
Router> show ?
clock Display the system clock
history Display the session command history
hosts IP domain-name, lookup style, nameservers, and host table
sessions Information about Telnet connections
terminal Display terminal configuration parameters
users Display information about terminal lines
version System hardware and software status
help
terminal full-help (EXEC)
To display a brief description of the help system, enter the help command.
helpThis command has no arguments or keywords.
Available in all command modes
The help command provides a brief description of the context-sensitive help system.
Enter the help command for a brief description of the help system:
Router# help
Help may be requested at any point in a command by entering
a question mark '?'. If nothing matches, the help list will
be empty and you must backup until entering a '?' shows the
available options.
Two styles of help are provided:
1. Full help is available when you are ready to enter a
command argument (e.g. 'show ?') and describes each possible
argument.
2. Partial help is provided when an abbreviated argument is entered
and you want to know what arguments match the input
(e.g. 'show pr?'.)
The following example shows how to use word help to display all the privileged EXEC commands that begin with the letters "co":
Router# co?
configure connect copy
The following example shows how to use command syntax help to display the next argument of a partially complete access-list command. One option is to add a wild-card mask. The <cr> symbol indicates that the other option is to press Return to execute the command.
Router(config)# access-list 99 deny 131.108.134.234 ?
A.B.C.D Mask of bits to ignore
<cr>
full-help
terminal full-help
To change the command history buffer size for a particular line, use the history size line configuration command. To disable the command history feature, use the no form of this command. (history enables history, no history disables history, and no history size resets to default.)
history size number-of-lines| number-of-lines | Number of command lines that the system will record in its history buffer. The range is 0 to 256. |
10 lines
Line configuration
The command history feature provides a record of EXEC commands you have entered. This feature is particularly useful for recalling long or complex commands or entries, including access lists.
Table 2-2 lists the keys and functions you can use to recall commands from the command history buffer.
| Key | Function |
|---|---|
| Ctrl-P or Up Arrow1 | Recalls commands in the history buffer in a backward sequence, beginning with the most recent command. Repeat the key sequence to recall successively older commands. |
| Ctrl-N or Down Arrow1 | Returns to more recent commands in the history buffer after recalling commands with Ctrl-P or the Up Arrow. Repeat the key sequence to recall successively more recent commands. |
In the following example, virtual terminal line 4 is configured with a history buffer size of 35 lines:
line vty 4
history size 35
show history
terminal history size
To prevent access to your session while keeping your connection open, enter the lock EXEC command at the system prompt.
lockThis command has no arguments or keywords.
EXEC
This command locks the keyboard. The global configuration command lockable must be included in the system configuration file for this command to work. The lock EXEC command remains in effect until the clear line privileged EXEC command is executed.
When this command is entered, the system prompts for a password, which can be any arbitrary string. The screen clears and displays the message "Locked." To regain access to the session, reenter the password.
The following example shows how to lock a session. The system prompts for a password, then verifies it. Once the "Locked" message displays, it will not be possible to use the terminal until the correct password is entered.
Router# lock
Password:
Again:
Locked
A dagger (+) indicates that the command is documented in another chapter.
clear line +
lockable +
To log in to a server, enter the login EXEC command at the system prompt.
loginThis command has no arguments or keywords.
EXEC
When you enter this command, the server prompts for a username and password. If you enter both correctly, the session becomes associated with the specified username. If there is no match, the connection reverts to the username with which the login command attempt was made, if applicable. If no login name and password were originally required, the connection reverts to a session that is not associated with any name.
When using the login command to access a system with TACACS security, you can type your name or specify a TACACS server user@hostname, user@IP address. The server must be one defined in a configuration with the tacacs-server host command.
If you do not specify a host, the router will try each of the TACACS servers in the list until it receives a response.
If you specify a host and that host does not respond, the router does not query another TACACS server. The router either denies access or behaves according to the action specified by the
tacacs-server last-resort command if there is one configured.
If you specify a TACACS server host with user@hostname, the TACACS server specified will be used for all subsequent authentication or notification queries, with the possible exception of SLIP address queries.
In the following example, a user wants to change the login name to led. The user enters the login command, the new name, and an incorrect password. The system rejects the attempt to change the username. Then the user attempts to change the login name to zep. The user enters the correct password and is allowed access to the EXEC at the user-level under the username of zep.
Router> login
Username: led
Password:
% Access denied
Still logged in as "usera"
Router> login
Username: zep
Password:
Router>
In the following example, user robert specifies TACACS host1 to authenticate his password:
Router> login
Username: robert@host1
Translating "HOST1"...domain server (131.108.1.111) [OK]
A dagger (+) indicates that the command is documented in another chapter.
logout
tacacs-server host +
tacacs-server last-resort +
username +
To close an active terminal session and terminate the EXEC, enter the logout EXEC command at the system prompt.
logoutThis command has no arguments or keywords.
EXEC
This command has the same function as the exit EXEC command.
The following example shows how to exit an active session:
logout
disconnect
exit
login (EXEC)
To assign a logical name to a connection, enter the name-connection EXEC command at the system prompt.
name-connectionThis command has no arguments or keywords.
EXEC
Use this command to assign a logical name to a physical connection. The EXEC prompts for the connection number and name to assign when you enter this command. The where command displays a list of the assigned logical connection names.
The following example checks the connection number for the host Eng1, assigns the logical name "my host" to it, and then confirms the assignment:
Router> where
Conn Host Address Byte Idle Conn Name
* 1 Eng1 192.31.6.22 0 0 Eng1
2 Term2 192.33.6.21 0 0 Term2
Router> name-connection
Connection number: 1
Enter logical name: my host
Connection 1 to Eng1 will be named "my host" [confirm]
Router> where
Conn Host Address Byte Idle Conn Name
* 1 Eng1 192.31.6.22 0 0 my host
2 Term2 192.33.6.21 0 0 Term2
connect
telnet
where
To return to a previous Telnet connection, enter the resume EXEC command at the system prompt.
resume [connection] [keyword]| connection | (Optional) Connection name or number; the default is the most recent connection. |
| keyword | (Optional) Keyword that can be set; see Table 2-3 for a list of keywords. |
| Keyword | Description |
| /line | Enables Telnet line mode. In this mode, the router does not send any data to the host until the user presses Return. The user can edit the line using the standard router command editing characters (Backspace, Delete, Ctrl-U, Ctrl-W). The /line keyword is a local switch; the remote server is not notified of the mode change. |
| /noline | Disables Telnet line mode and enables character-at-a-time mode (default). |
| /debug | Enables Telnet debugging mode. |
| /nodebug | Disables Telnet debugging mode (default). |
| /stream | Turns on stream processing, which enables a raw TCP stream with no Telnet control sequences. A stream connection does no processing of Telnet options and may be appropriate for connections to ports running UUCP and other non-Telnet protocols. |
| /nostream | Turns off stream processing, which enables the Telnet protocol (default). |
| /echo | Enables local echoing of characters (default). The /echo keyword is a local switch; the remote server is not notified of the state change. |
| /noecho | Disables local echoing of characters. |
| /set | Sets X3 connection options. |
EXEC
Use this command after you have escaped out of a session to move to another open connection. You can omit the command word resume and simply type the connection number to resume a connection. You can also return to the most recent session by simply pressing the Return key.
The following example resumes connection 2 in Telnet line mode:
Router> resume 2 /line
The following example resumes Telnet connection 3:
Router> 3
connect
telnet
To allow Finger protocol requests (defined in RFC 742) to be made of the network server, use the service finger global configuration command. This service is equivalent to issuing a remote show users command. The no service finger command removes this service.
service fingerThis command has no arguments or keywords.
Enabled
Global configuration
The following is an example of how to disable the Finger protocol:
no service finger
To list the commands you have entered in the current EXEC session, use the show history EXEC command.
show historyThis command has no arguments or keywords.
EXEC
The command history feature provides a record of EXEC commands you have entered. The number of commands the history buffer will record is determined by the history size line configuration command or the terminal history size EXEC command.
Table 2-4 lists the keys and functions you can use to recall commands from the command history buffer.
| Key | Function |
|---|---|
| Ctrl-P or Up Arrow | Recalls commands in the history buffer in a backward sequence, beginning with the most recent command. Repeat the key sequence to recall successively older commands. |
| Ctrl-N or Down Arrow | Returns to more recent commands in the history buffer after recalling commands with Ctrl-P or the Up Arrow. Repeat the key sequence to recall successively more recent commands. |
The following is sample output from the show history command, which lists the commands the user has entered in EXEC mode for this session:
Router# show history
help
where
show hosts
show history
Router#
history size
terminal history size
To display a terminal line's parameters, use the show line EXEC command.
show line [line-number]| line-number | (Optional) Absolute line number of the line for which you want to list parameters. |
EXEC
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.
Router# show line 2
Tty Typ Tx/Rx A Modem Roty AccO AccI Uses Noise Overruns
2 VTY 9600/9600 - - - - - 0 0 0/0
Line 2, Location: "", Type: ""
Length: 24 lines, Width: 80 columns
Baud rate (TX/RX) is 9600/9600
Status: No Exit Banner
Capabilities: none
Modem state: Idle
Special Chars: Escape Hold Stop Start Disconnect Activation
^^x none - - none
Timeouts: Idle EXEC Idle Session Modem Answer Session Dispatch
0:10:00 never 0:00:15 not imp not set
Session limit is not set.
Editing is enabled.
History is enabled, history size is 10.
Allowed transports are telnet mop. Preferred is telnet.
No output characters are padded
Characters causing immediate data dispatching:
Char ASCII
Use the show sessions EXEC command to show the active Telnet sessions.
show sessionsThis command has no arguments or keywords.
EXEC
The following is sample output from the show sessions command:
Router# show sessions
Conn Host Address Byte Idle Conn Name
1 MATHOM 192.31.7.21 0 0 MATHOM
* 2 CHAFF 131.108.12.19 0 0 CHAFF
In the display, an asterisk (*) indicates your current terminal session.
Table 2-5 describes the fields shown in the display.
| Field | Description |
|---|---|
| Conn | Name or address of the remote host to which the connection is made. |
| Host | Remote host to which the router is connected through a Telnet session. |
| Address | IP address of the remote host. |
| Byte | Number of unread bytes that are waiting for the user to see on the connection. |
| Idle | Interval (in minutes) since data was last sent on the line. |
| Conn Name | Assigned name of the connection. |
Use the show tcp EXEC command to display the status of TCP connections.
show tcp [line-number]| line-number | (Optional) Absolute line number of the line for which you want to display Telnet connection status. |
EXEC
The following is sample output from the show tcp command:
Router# show tcp
con0 (console terminal), connection 1 to host MATHOM
Connection state is ESTAB, I/O status: 1, unread input bytes: 1
Local host: 192.31.7.18, 33537 Foreign host: 192.31.7.17, 23
Enqueued packets for retransmit: 0, input: 0, saved: 0
Event Timers (current time is 2043535532):
Timer: Retrans TimeWait AckHold SendWnd KeepAlive
Starts: 69 0 69 0 0
Wakeups: 5 0 1 0 0
Next: 2043536089 0 0 0 0
iss: 2043207208 snduna: 2043211083 sndnxt: 2043211483 sndwnd: 1344
irs: 3447586816 rcvnxt: 3447586900 rcvwnd: 2144 delrcvwnd: 83
RTTO: 565 ms, RTV: 233 ms, KRTT: 0 ms, minRTT: 68 ms, maxRTT: 1900 ms
ACK hold: 282 ms
Datagrams (max data segment is 536 bytes):
Rcvd: 106 (out of order: 0), with data: 71, total data bytes: 83
Sent: 96 (retransmit: 5), with data: 92, total data bytes: 4678
Table 2-6 describes the following lines of output shown in the display:
con0 (console terminal), connection 1 to host MATHOM
Connection state is ESTAB, I/O status: 1, unread input bytes: 1
Local host: 192.31.7.18, 33537 Foreign host: 192.31.7.17, 23
Enqueued packets for retransmit: 0, input: 0, saved: 0
| Field | Description |
|---|---|
| con0 | Identifying number of the line. |
| (console terminal) | Location string. |
| connection 1 | Number identifying the TCP connection. |
| to host MATHOM | Name of the remote host to which the connection has been made. |
| Connection state is ESTAB | A connection progresses through a series of states during its lifetime. These states follow in the order in which a connection progresses through them.
For more information, see RFC 793, Transmission Control Protocol Functional Specification. |
| I/O status: 1 | Number describing the current internal status of the connection. |
| unread input bytes: 1 | Number of bytes that the lower-level TCP processes have read, but the higher level TCP processes have not yet processed. |
| Local host: 192.31.7.18 | Internet address of the network server. |
| 33537 | Local port number, as derived from the following equation: line-number + (512 * random-number). (The line number uses the lower nine bits; the other bits are random.) |
| Foreign host: 192.31.7.17 | Internet address of the remote host to which the TCP connection has been made. |
| 23 | Destination port for the remote host. |
| Enqueued packets for retransmit: 0 | Number of packets waiting on the retransmit queue. These are packets on this TCP connection that have been sent but have not yet been acknowledged by the remote TCP host. |
| input: 0 | Number of packets that are waiting on the input queue to be read by the user. |
| saved: 0 | Number of received out-of-order packets that are waiting for all packets comprising the message to be received before they enter the input queue. For example, if packets 1, 2, 4, 5, and 6 have been received, packets 1 and 2 would enter the input queue, and packets 4, 5, and 6 would enter the saved queue. |
The following line of output shows the current time according to the system clock of the local host.
Event Timers (current time is 2043535532):
The time shown is the number of milliseconds since the system started.
The following lines of output display the number of times that various local TCP timeout values were reached during this connection. In this example, the router retransmitted 69 times because it received no response from the remote host, and it transmitted an ACK many more times because there was no data on which to piggyback.
Timer: Retrans TimeWait AckHold SendWnd KeepAlive
Starts: 69 0 69 0 0
Wakeups: 5 0 1 0 0
Next: 2043536089 0 0 0 0
Table 2-7 describes the fields in the preceding lines of output.
| Field | Description |
|---|---|
| Timer: | This line of output indicates the names of the timers in the display. |
| Starts: | The number of times the timer has been started during this connection. |
| Wakeups: | The Wakeups row of the KeepAlives column shows how many keepalives have been transmitted without receiving any response. (This field is reset to zero when a response is received.) |
| Next: | The system clock setting that will trigger the next time this timer will go off. |
| Retrans | The Retransmission timer is used to time TCP packets that have not been acknowledged and are waiting for retransmission. |
| TimeWait | The TimeWait timer is used to ensure that the remote system receive a request to disconnect a session. |
| AckHold | The Acknowledgment timer is used to delay the sending of acknowledgments to the remote TCP in an attempt to reduce network use. |
| SendWnd | The Send Window is used to ensure that there is no closed window due to a lost TCP acknowledgment. |
| KeepAlive | The KeepAlive timer is used to control the transmission of test messages to the remote TCP to ensure that the link has not been broken without the local TCP's knowledge. |
The following lines of output display the sequence numbers that TCP uses to ensure sequenced, reliable transport of data. The router and remote host each use these sequence numbers for flow control and to acknowledge receipt of datagrams. Table 2-8 describes the specific fields in these lines of output:
iss: 2043207208 snduna: 2043211083 sndnxt: 2043211483 sndwnd: 1344
irs: 3447586816 rcvnxt: 3447586900 rcvwnd: 2144 delrcvwnd: 83
| Field | Description |
|---|---|
| iss: 2043207208 | Initial send sequence number. |
| snduna: 2043211083 | Last send sequence number the router has sent but has not received an acknowledgment for. |
| sndnxt: 2043211483 | Sequence number the router will send next. |
| sndwnd: 1344 | TCP window size of the remote host. |
| irs: 3447586816 | Initial receive sequence number. |
| rcvnxt: 3447586900 | Last receive sequence number the router has acknowledged. |
| rcvwnd: 2144 | Router's TCP window size. |
| delrcvwnd: 83 | Delayed receive window--data the router has read from the connection, but has not yet subtracted from the receive window the router has advertised to the remote host. The value in this field gradually increases until it is larger than a full-sized packet, at which point it is applied to the rcvwnd field. |
The following lines of output display values that the router uses to keep track of transmission times so that TCP can adjust to the network it is using. Table 2-9 describes the fields in the following line of output:
RTTO: 565 ms, RTV: 233 ms, KRTT: 0 ms, minRTT: 68 ms, maxRTT: 1900 ms
ACK hold: 282 ms
| Field | Description |
|---|---|
| RTTO: 565 ms | Round trip timeout. |
| RTV: 233 ms | Variance of the round trip time. |
| KRTT: 0 ms | New round trip timeout (using the Karn algorithm). This field separately tracks the round trip time of packets that have been retransmitted. |
| minRTT: 68 ms | Smallest recorded round trip timeout (hard wire value used for calculation). |
| maxRTT: 1900 ms | Largest recorded round trip timeout. |
| ACK hold: 282 ms | Time the router will delay an acknowledgment in order to piggyback data on it. |
For more information on these fields, refer to "Round Trip Time Estimation," P. Karn & C. Partridge, ACM SIGCOMM-87, August 1987.
Table 2-10 describes the fields in the following lines of output:
Datagrams (max data segment is 536 bytes):
Rcvd: 106 (out of order: 0), with data: 71, total data bytes: 83
Sent: 96 (retransmit: 5), with data: 92, total data bytes: 4678
| Field | Description |
|---|---|
| Rcvd: 106 (out of order: 0) | Number of datagrams the local host has received during this connection (and the number of these datagrams that were out of order). |
| with data: 71 | Number of these datagrams that contained data. |
| total data bytes: 83 | Total number of bytes of data in these datagrams. |
| Sent: 96 (retransmit: 5) | Number of datagrams the local host sent during this connection (and the number of these datagrams that had to be retransmitted). |
| with data: 92 | Number of these datagrams that contained data. |
| total data bytes: 4678 | Total number of bytes of data in these datagrams. |
Use the show terminal EXEC command to obtain information about the terminal configuration parameter settings for the current terminal line.
show terminalThis command has no arguments or keywords.
EXEC
The following is sample output from the show terminal command:
Router# show terminal
Line 2, Location: "", Type: ""
Length: 24 lines, Width: 80 columns
Baud rate (TX/RX) is 9600/9600
Status: Ready, Active, No Exit Banner
Capabilities: Enabled
Modem state: Ready
Special Chars: Escape Hold Stop Start Disconnect Activation
^^x none - - none
Timeouts: Idle EXEC Idle Session Modem Answer Session Dispatch
never never 0:00:15 not imp not set
Session limit is not set.
Allowed transports are telnet rlogin. Preferred is telnet
No output characters are padded
Table 2-11 describes the fields in the first three lines of show terminal output.
| Field | Description |
|---|---|
| Line 2 | Current terminal line. |
| Location: "" | Location of the current terminal line, as specified using the location line configuration command. |
| Type: "" | Type of the current terminal line, as specified using the line global configuration command. |
| Length: 24 lines | Length of the terminal display. |
| Width: 80 columns | Width of the terminal display, in character columns. |
| Baud rate (TX/RX) is 9600/9600 | Transmit rate/receive rate of the line. |
The following line of output indicates the status of the line:
Status: Ready, Active, No Exit Banner
Table 2-12 describes possible values for the Status field.
| Field | Description |
|---|---|
| Active | A process is actively using the line. |
| Autobauding | The line is running the autobaud process. |
| Carrier Dropped | Some sense of "carrier" has been dropped, so the line process should be killed. |
| Connected | The line has at least one active connection. |
| Dialing Out | A DDR async interface is dialing a remote site on this line. |
| Echo Off | The line is not echoing what the user types in (because a password must be entered, for example). |
| Escape Started | The first character of the escape sequence has been typed. |
| Escape Typed | Both characters of the escape sequence have been typed. |
| Hanging Up | The line state is "hanging up." |
| Hardware XON/XOFF | The line uses a UART that supports XON/XOFF flow control in hardware. (This does not mean that the line is currently using software flow control.) |
| Hold Typed | The user typed the "hold character" (and the line is paused). |
| Idle | The line modem state is "idle" (see modem state diagrams). |
| Idle Timeout | An idle timeout has occurred. |
| Input Stopped | The input has been turned off due to hardware flow control or overflow. |
| No Exit Banner | The normal exit banner will not be displayed on this line. |
| PSI Enabled | The line is paying attention to typed escape characters. |
| Rcvd BREAK | A BREAK sequence has been received on the line. |
| Rcvd Command | The line has received a special command sequence (four example, ^^B for send break). |
| Rcvd CR | The last character received was a carriage return. |
| Ready | The line state is "ready." |
| Ring Transition | There has been a transition on the RING signal of the line. |
| Send Break Soon | You need to send a BREAK on the line soon. |
| Send XOFF Soon | Your buffers are full and you should send an XOFF soon. |
| Sending Break | You are in the process of sending a BREAK sequence on the line. |
| Sent XOFF | Your buffers were full, so we sent an XOFF. |
| SLIP Mode | The line is running SLIP or PPP. |
The following line of output indicates the status of the capabilities of the line; these capabilities correspond closely to configurable parameters that can be set using configuration commands.
Capabilities: Enabled
Table 2-13 describes possible values for the Capabilities field.
| Field | Description |
|---|---|
| Autobaud Full Range | Corresponds to the autobaud command. |
| Character Padding | At least one pad c x configuration command has been used. |
| Enabled | The user has "enabled" successfully. |
| EXEC Suppressed | Corresponds to the no exec command. |
| Hangup on Last Close | Corresponds to the autohangup command. |
| Hardware Flowcontrol In | Corresponds to the flowcontrol hardware in command. |
| Hardware Flowcontrol Out | Corresponds to the flowcontrol hardware out command. |
| Insecure | Corresponds to the insecure command. |
| Lockable | Corresponds to the lockable command. |
| Modem Callin | Corresponds to the modem callin command. |
| Modem Callout | Corresponds to the modem callout command. |
| Modem CTS-Required | Corresponds to the modem cts-required command. |
| Modem DTR-Active | Corresponds to the modem dtr-active command. |
| Modem RI is CD | Corresponds to the modem ri-is-cd command. |
| No Login Banner | Corresponds to the no exec-banner command. |
| Notification Set | Corresponds to the notify command. |
| Output Non-Idle | Corresponds to the session-timeout N output command. |
| Permanent SLIP | Corresponds to the slip-dedicated command |
| Private Line | Corresponds to the private command. |
| Refuse Suppress-GA | Corresponds to the telnet refuse command. |
| Receives Logging Output | Corresponds to the monitor command. |
| Refuse Telnet Echo | Corresponds to the telnet refuse command. |
| Send BREAK on IP | Corresponds to the telnet break-on-ip command. |
| SLIP allowed | Corresponds to the slip address xxxx command. |
| Software Flowcontrol In | Corresponds to the flowcontrol software in command. |
| Software Flowcontrol Out | Corresponds to the flowcontrol software out command. |
| Telnet Transparent Mode | Corresponds to the telnet transparent command. |
The following line of output indicates the modem state. Possible values include Autobauding, Carrier Dropped, Hanging Up, Idle, and Ready.
Modem state: Ready
The following lines of output indicate the special characters that can be entered to activate various terminal operations. The none or hyphen (-) values imply that no special characters are set.
Special Chars: Escape Hold Stop Start Disconnect Activation
^^x none - - none
The following lines of output indicate the timeout values that have been configured for the line:
Timeouts: Idle EXEC Idle Session Modem Answer Session Dispatch
never never 0:00:15 not imp not set
Table 2-14 describes the fields in the preceding lines of output.
The following lines of output indicate how various options have been configured:
Session limit is not set.
Allowed transports are telnet rlogin. Preferred is telnet
No output characters are padded
Use the show users EXEC command to display information about the active ports of the router. The information displayed includes the line number, connection name, idle time, and terminal location.
show users [all]| all | (Optional) Specifies that all lines, whether or not anyone is using them, be displayed. |
EXEC
The following is sample output from the show users command:
Router# show users
Line User Host(s) Idle Location
0 con 0 idle
* 2 vty 0 rdoe idle 0 ABC.CISCO.COM
Table 2-15 describes the fields shown in the display.
| Field | Description |
|---|---|
| Line | Contains three subfields. The asterisk (*) identifies the line of the user entering the show command.
The first subfield (2, in this case) is the absolute line number. The second subfield (vty, in this case) indicates the type of line. Possible values follow:
The third subfield (0, in this case) indicates the relative line number within type. |
| User | Name of user using the line. If this field is blank, no user is using the line. |
| Host(s) | Host to which the user is connected (outgoing connection). A value of idle indicates no outgoing connection to a host. |
| Idle | Interval (in minutes) since the user has typed something. |
| Location | Either the hardwired location for the line or, if there is an incoming connection, the host the incoming connection is from. |
The following is sample output from the show users all command:
Router> show users all
Line User Host(s) Idle Location
0 con 0
1 aux 0
* 2 vty 0 idle 0 USER.COMPANY.COM
3 vty 1
4 vty 2
5 vty 3
6 vty 4
A dagger (+) indicates that the command is documented in another chapter.
line +
location +
To display information about the active ports of the router, use the systat EXEC command.
systat [all]| all | (Optional) Displays information for both active and inactive ports. |
EXEC
This command is a synonym for the show users command.
The following example shows how to use the systat command:
Router> systat all
Line User Host(s) Idle Location
0 con 0
1 aux 0
* 2 vty 0 cma idle 0 USER-MAC.COMPANY.COM
3 vty 1 idle 0 NAME.COMPANY.COM
4 vty 2
5 vty 3
6 vty 4
Table 2-16 describes the fields shown in the display.
| Field | Description |
|---|---|
| Line | Contains three subfields. The asterisk (*) identifies the line of the user entering the command.
The first subfield (2, in this case) is the absolute line number. The second subfield (vty, in this case) indicates the type of line. Possible values follow:
The third subfield (0, in this case) indicates the relative line number within type. |
| User | Name of user using the line. If this field is blank, no user is using the line. |
| Host(s) | Host to which the user is connected (outgoing connection). A value of idle indicates no outgoing connection to a host. |
| Idle | Interval (in minutes) since the user has typed something. |
| Location | Either the hardwired location for the line or, if there is an incoming connection, the host the incoming connection is from. |
To start a Telnet connection, enter the telnet EXEC command.
telnet host [port] [keyword]| host | A host name or an Internet address. |
| port | (Optional) Decimal TCP port number; the default is the Telnet server port (decimal 23) on the host. |
| keyword | (Optional) Keyword that can be set with the connection; see Table 2-17 for a list of keywords. |
| Keyword | Description |
|---|---|
| /route: path | Specifies loose source routing. The argument path is a list of host names or Internet addresses that specifies network nodes, ending with the final destination. |
| /line | Enables Telnet line mode. In this mode, the router does not send any data to the host until you press Return. You can edit the line using the standard router command editing characters (Backspace, Delete, Ctrl-U, Ctrl-W). The /line keyword is a local switch; the remote server is not notified of the mode change. |
| /debug | Enables Telnet debugging mode. |
| /echo | Enables local echoing of characters (default). The /echo keyword is a local switch; the remote server is not notified of the state change. |
| /stream | Turns on stream processing, which enables a raw TCP stream with no Telnet control sequences. A stream connection does not process Telnet options and may be appropriate for connections to ports running UUCP and other non-Telnet protocols. |
EXEC
The router assigns a logical name to each connection; several commands use these names to identify connections. The logical name is the same as the host name, unless that name is already in use or you change the connection name with the EXEC command name-connection. If the name is already in use, the router assigns a null name to the connection.
To obtain an onscreen list of Telnet special sequence commands, enter the Ctrl-^? sequence at the EXEC prompt. The system administrator can change the escape character portion of this sequence; use the show terminal EXEC command to check the current setting for the escape character. To enter the escape sequence, press and hold the Ctrl, Shift, and 6 keys, then let go and press the X key.
The following example routes packets from the source system to kl.sri.com, then to 10.1.0.11, and finally to mathom:
Router> connect mathom /route:kl.sri.com 10.1.0.11 mathom
The following example connects to a host with logical name mathom:
Router> mathom
The following example shows the on-line table displayed when the Ctrl-^-? sequence is entered. (Note that the sequence will not appear on your terminal.)
Router> <Ctrl-^ ?>
[Special telnet escape help]
^^B sends telnet BREAK
^^C sends telnet IP
^^H sends telnet EC
^^O sends telnet AO
^^T sends telnet AYT
^^U sends telnet EL
connect
name-connection
To set the number of data bits per character that are interpreted and generated by software for the current line, use the terminal data-character-bits EXEC command.
terminal data-character-bits {7 | 8}| 7 | Seven data bits per character |
| 8 | Eight data bits per character |
8 data bits per character
EXEC
The terminal data-character-bits command is used primarily to strip parity from X.25 connections on IGS or Cisco 3000 routers with the protocol translation software option. The terminal data-character-bits command does not work on hardwired lines.
The following example shows how to change the data bits per character to 7:
terminal data-character-bits 7
To set the number of data bits per character that are interpreted and generated by hardware for the current terminal line, use the terminal databits EXEC command.
terminal databits {5 | 6 | 7 | 8}| 5 | Five databits per character |
| 6 | Six databits per character |
| 7 | Seven databits per character |
| 8 | Eight databits per character |
8 data bits per character
EXEC
The terminal databits command can be used to mask the high bit on input from devices that generate 7 data bits with parity. If parity is being generated, specify 7 data bits per character. If no parity generation is in effect, specify 8 data bits per character. The other keywords are supplied for compatibility with older devices and generally are not used.
The following example shows how to change the data bits per character to 7:
terminal databits 7
To define a character that causes a packet to be sent for the current terminal line, use the terminal dispatch-character EXEC command. Use the terminal no dispatch-character command to remove the dispatch characters.
terminal dispatch-character ascii-number1 [ascii-number2 . . . ascii-number]None
EXEC
This command defines a dispatch character that causes packets 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. See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example defines the characters Ctrl-D and Ctrl-Y as the dispatch characters:
terminal dispatch-character 4 25
terminal dispatch-timeout
To set the character dispatch timer for the current terminal line, use the terminal dispatch-timeout EXEC command. The terminal no dispatch-timeout command removes the timeout definition.
terminal dispatch-timeout milliseconds| milliseconds | An 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, thus increasing the processing efficiency of the remote host. |
None
EXEC
The terminal dispatch-timeout 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 terminal dispatch-timeout and terminal dispatch-character 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:
terminal dispatch-timeout 80
terminal dispatch-character
To temporarily set the ability of a line to act as a transparent pipe for file transfers, use the terminal download EXEC command. Use the terminal no download command to remove this ability.
terminal downloadThis command has no arguments or keywords.
Disabled
EXEC
Use the terminal download command when running a program such as Kermit, Xmodem, or CrossTalk that downloads a file across a router line.
The following example shows how to set up the current line for a Kermit file transfer:
terminal download
To enable the enhanced editing mode on the local line, use the terminal editing EXEC command. To disable the enhanced editing mode on the current line, use the no form of this command.
terminal editingThis command has no arguments or keywords.
Enabled
EXEC
Table 2-18 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, or carrying out, a command. At the "---More---" prompt on a terminal screen, pressing the Return key scrolls down a line. |
| Space Bar | Scrolls down a page 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 continue to press the left arrow key at any time 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 key stroke 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. |
The editing keys and functions of the earlier software release are listed in Table 2-19.
| 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 mode editing is reenabled for the current terminal session:
terminal editing
A dagger (+) indicates that the command is documented in another chapter.
editing +
To set the escape character for the current terminal line, use the terminal escape-character EXEC command. The terminal no escape-character command sets the escape character to Break.
terminal escape-character ascii-number| ascii-number | Either the ASCII decimal representation of the desired escape character or a control sequence (Ctrl-P, for example). |
Ctrl-^
EXEC
Typing the escape character followed by the X key returns you to the EXEC when you are connected to another computer. See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example sets the escape character to Ctrl-P (ASCII decimal 16).
terminal escape-character 16
To change the ASCII character widths for characters entered for the current terminal line, use the terminal exec-character-bits EXEC command.
terminal exec-character-bits {7 | 8}| 7 | Selects the 7-bit ASCII character set. |
| 8 | Selects the full 8-bit character set. |
7-bit ASCII character set
EXEC
This EXEC command overrides the default-value exec-character-bits global configuration command. Configuring the EXEC character width to 8 bits allows you to add special graphical and international characters in banners, prompts, and so forth.
When the user exits the system, the character width is reset to the default value established by the global configuration command. However, setting the EXEC character width to 8 bits can also cause failures. If a user on a terminal that is sending parity enters the 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 temporarily configures a router to use a full 8-bit user interface for system banners and prompts. This allows the use of additional graphical and international characters.
terminal exec-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 +
special-character-bits +
terminal special-character-bits
To set up the method of data flow control for the current terminal line, use the terminal flowcontrol EXEC command.
terminal flowcontrol {none | software [in | out] | hardware}| none | Prevents flowcontrol. |
| 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 directions are assumed. |
| hardware | Sets hardware flow control. For information about setting up the RS-232 line, see the hardware manual for your product. |
By default, no flow control method is set. This default is returned with the none keyword. For software flow control, the default stop and start characters are Ctrl-S and Ctrl-Q (XOFF and XON). You can change them with the terminal stop-character and terminal start-character commands.
EXEC
This command pertains to the auxiliary port only.
The following example sets incoming software flow control:
terminal flowcontrol software in
terminal start-character
terminal stop-character
To get help for the full set of user-level commands, use the terminal full-help EXEC command.
terminal full-helpThis command has no arguments or keywords.
Disabled
EXEC
The terminal full-help command enables (or disables) a user to see all of the help messages available from the terminal. It is used with the show command.
The following example is output for show? with terminal full-help enabled.
router> terminal full-help
router> show?
access expression List access expression
access lists List access lists
apollo Apollo network information
appletalk AppleTalk information
arp ARP table
async Information on terminal lines used as router interfaces
...
full-help
help
To change the command history buffer size for the current terminal session, use the terminal history size EXEC command. To revert to the default value, use the no form of this command.
terminal history size number-of-lines| number-of-lines | Number of command lines that the system will record in its history buffer. The range is 0 to 256. |
10 lines
EXEC
The command history feature provides a record of EXEC commands you have entered. This feature is particularly useful to recall long or complex commands or entries, including access lists.
Table 2-20 lists the keys and functions you can use to recall commands from the history buffer.
| Key | Function |
|---|---|
| Ctrl-P or Up Arrow1 | Recalls commands in the history buffer in a backward sequence, beginning with the most recent command. Repeat the key sequence to recall successively older commands. |
| Ctrl-N or Down Arrow1 | Returns to more recent commands in the history buffer after recalling commands with Ctrl-P or the Up Arrow. Repeat the key sequence to recall successively more recent commands. |
In the following example, the number of command lines recorded is set to 15 for the local line:
terminal history size 15
history size
show history
To set the hold character, use the terminal hold-character EXEC command. Use the terminal no hold-character command to restore the default.
terminal hold-character ascii-number| ascii-number | Either the ASCII decimal representation of the hold character or a control sequence (for example, Ctrl-P). |
None
EXEC
Typing the hold character temporarily halts the output at the terminal. To continue the output, type any other character. To send the hold character to the host, precede it with the escape character.
The Break character is represented by zero; NULL cannot be represented.
See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example removes the previously set hold character:
terminal no hold-character
A dagger (+) indicates that the command is documented in another chapter.
hold-character +
To set the number of lines on the current terminal screen, use the terminal length EXEC command. The terminal no length command is the same as entering a value of zero.
terminal length screen-length| screen-length | The desired number of lines. The router uses this value to determine when to pause during multiple-screen output. The default length is 24 lines. A value of zero disables pausing between screens of output. |
24 lines
EXEC
The screen length specified can be learned by remote hosts.
The following example disables pausing between screen output:
terminal length 0
To set the ability to display debug command output and system error messages to the current terminal, use the terminal monitor EXEC command. Use the terminal no monitor command to disable this ability.
terminal monitorThis command has no arguments or keywords.
Disabled
EXEC
To use this command, you must first issue the enable command and enter the password to access the privileged EXEC command mode.
The following example illustrates how to enable the system debugging messages on the local terminal screen:
terminal monitor
To enable terminal notification about pending output from other connections, use the terminal notify EXEC command. Use the terminal no notify command to end such notifications.
terminal notifyThis command has no arguments or keywords.
Disabled
EXEC
This 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. When you have multiple concurrent connections, you might want to know when output is pending on a connection other than the current connection. For example, you might want to know when another connection receives mail or a message. The terminal notify command causes the router to notify you of pending output.
The following example sets up notification to the current line of e-mail messages on the other open connection:
terminal notify
To set the padding on a specific output character for the current terminal line, use the terminal padding EXEC command. The terminal no padding command removes padding for the specified output character.
terminal padding ascii-number count| ascii-number | ASCII decimal representation of the character. |
| count | Number of NULL bytes sent after the ASCII character, up to 255 padding characters in length. |
None
EXEC
See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example pads Ctrl-D (ASCII 4) with 164 NULL bytes:
terminal padding 4 164
To define the generation of the parity bit for the current terminal line, use the terminal parity EXEC command.
terminal parity {none | even | odd | space | mark}| none | No parity |
| even | Even parity |
| odd | Odd parity |
| space | Space parity |
| mark | Mark parity |
No parity
EXEC
The following example shows how to set the parity bit to odd:
terminal parity odd
To set the terminal baud rate receive (from terminal) speed for the current terminal line, use the terminal rxspeed EXEC command.
terminal rxspeed bps| bps | Baud rate in bits per second (bps); see Table 2-21 for settings. |
9600 bps
EXEC
Use Table 2-21 as a guide for setting the line speeds.
| Router Model | Baud Rates |
|---|---|
| Cisco 7000 series, AGS, CGS, MGS | 50, 75, 110, 134, 150, 200, 300, 600, 1050, 1200, 2000, 2400, 4800, 9600, 19200, 38400 |
| Cisco 2000, Cisco 3000, Cisco 4000 | 75, 110, 134, 150, 300, 600, 1200, 1800, 2000, 2400, 4800, 9600, 19200, 38400 |
The following example sets the current auxiliary line receive speed to 2400 bps:
terminal rxspeed 2400
terminal speed
terminal txspeed
To change the ASCII character widths to accept special characters for the current terminal line, use the terminal special-character-bits EXEC command.
terminal special-character-bits {7 | 8}| 7 | Selects the 7-bit ASCII character set. |
| 8 | Selects the full 8-bit character set. |
7-bit ASCII character set
EXEC
The terminal special-character-bits command temporarily allows the server to support international character sets. It overrides the default-value special-character-bits global configuration command and is used to compare character sets typed by the user with the special character available during a data connection, which includes software flow control and escape characters. Configuring the width to 8 allows you to use twice as many special characters as with the 7-bit setting. When the user exits the system, the command is reset to the default value established by the global configuration command.
The following example temporarily configures full 8-bit comparisons of flow control and interrupt characters to allow more special characters to be accepted. When you exit the system, character width will be reset to the width established by the global configuration command.
terminal 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 +
special-character-bits +
terminal exec-character-bits
To set the terminal baud rate for the current terminal line, use the terminal speed EXEC command. The command sets both the transmit (to terminal) and receive (from terminal) speeds.
terminal speed bps| bps | Baud rate in bits per second (bps), see Table 2-22 for settings. |
9600 bps
EXEC
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 2-22 as a guide for setting the line speeds.
| Router Model | Baud Rates |
|---|---|
| Cisco 7000 series, AGS, CGS, MGS | 50, 75, 110, 134, 150, 200, 300, 600, 1050, 1200, 2000, 2400, 4800, 9600, 19200, 38400 |
| 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 current auxiliary line receive and transmit speed to 2400 bps:
terminal speed 2400
terminal rxspeed
terminal txspeed
To set the flow control stop character for the current terminal line, use the terminal start-character EXEC command. The command defines the character that signals the start of data transmission when software flow control is in effect. Use the terminal no start-character command to remove the start character.
terminal start-character ascii-number| ascii-number | ASCII decimal representation of the start character. |
Ctrl-Q (ASCII character 17)
EXEC
See the "ASCII Character Set" appendix for a list of ASCII characters.
The following example changes the start character to Ctrl-O (ASCII decimal 15):
terminal start-character 15
A dagger (+) indicates that the command is documented in another chapter.
start-character +
To set the flow control stop character for the current terminal line, use the terminal stop-character EXEC command. The command defines the character that signals the end of data transmission when software flow control is in effect. The terminal no stop-character command removes the character.
terminal stop-character ascii-number| ascii-number | ASCII decimal representation of the stop character. |
Ctrl-S (ASCII character 19)
EXEC
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:
terminal stop-character 5
A dagger (+) indicates that the command is documented in another chapter.
stop-character +
To set the number of stop bits transmitted per byte by the current terminal line, use the terminal stopbits EXEC command.
terminal stopbits {1 | 1.5 | 2}| 1 | One stop bit |
| 1.5 | One and a half stop bits |
| 2 | Two stop bits |
2 stop bits
EXEC
The following example illustrates how to change the stop bits to 1:
terminal stopbits 1
A dagger (+) indicates that the command is documented in another chapter.
stopbits +
To cause the system to generate a hardware Break signal on the RS-232 line that is associated with a reverse Telnet connection for the current line, use the terminal telnet break-on-ip EXEC command.
terminal telnet break-on-ipThis command has no arguments or keywords.
None
EXEC
Occurs when a Telnet Interrupt-Process (IP) command is received on that connection. This command can be used to control the translation of Telnet IP commands into X.25 Break indications.
This command is also a useful workaround in the following situations:
The following example shows how to generate a Break signal on the RS-232 line:
line aux 0
terminal telnet break-on-ip
A dagger (+) indicates that the command is documented in another chapter.
telnet (EXEC) +
telnet break-on-ip +
To set the current line to refuse to negotiate full duplex, remote echo options on incoming connections, use the terminal telnet refuse-negotiations EXEC command.
terminal telnet refuse-negotiationsThis command has no arguments or keywords.
None
EXEC
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
terminal telnet refuse-negotiations
A dagger (+) indicates that the command is documented in another chapter.
telnet (EXEC) +
telnet refuse-negotiations +
To allow the router to negotiate transmission speed for the current line, use the terminal telnet speed EXEC command.
terminal 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
EXEC
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 bps. If the remote host requests a speed of greater than 9600 bps, then 9600 bps will be used.
line aux 0
terminal telnet speed 2400 9600
A dagger (+) indicates that the command is documented in another chapter.
telnet (EXEC) +
telnet speed +
To cause the router to send a Telnet Synchronize signal when it receives a Telnet Break signal on the current line, use the terminal telnet sync-on-break EXEC command.
terminal telnet sync-on-breakThis command has no arguments or keywords.
None
EXEC
The following example shows how to set the auxiliary port to cause the router to send a Telnet synchronize signal:
line aux 0
terminal telnet sync-on-break
A dagger (+) indicates that the command is documented in another chapter.
telnet (EXEC) +
telnet sync-on-break +
To cause the router to send a Return (CR) as a CR followed by a NULL instead of a CR followed by a Line Feed (LF) on the current line, use the terminal telnet transparent EXEC command.
terminal telnet transparentThis command has no arguments or keywords.
None
EXEC
This command is useful for coping with different interpretations of end-of-line handling in the Telnet protocol specification.
The following example sets the router, when sending a CR, to send a CR followed by a NULL character:
terminal telnet transparent
A dagger (+) indicates that the command is documented in another chapter.
telnet (EXEC) +
telnet transparent +
To specify the type of terminal connected to the current line, use the terminal terminal-type EXEC command. The command records the type of terminal connected to the line. The terminal no terminal-type command removes any information about the type of terminal and resets the line to the default terminal emulation.
terminal terminal-type terminal-name| terminal-name | Terminal name and type. |
VT100
EXEC
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 as a type VT220 during the current session:
terminal terminal-type VT220
A dagger (+) indicates that the command is documented in another chapter.
terminal-type +
To specify a default transport protocol for the router to use for the current session (if the user does not specify a protocol), use the terminal transport EXEC command. Also use to prevent any connection attempts.
terminal transport {telnet | none}| 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. |
telnet
EXEC
The following example illustrates how to configure the console to not try to connect when an unrecognized command is entered:
terminal transport none
A dagger (+) indicates that the command is documented in another chapter.
transport preferred +
To set the terminal transmit baud rate (to terminal) on the current terminal line, use the
terminal txspeed EXEC command.
| bps | Baud rate in bits per second (bps); see Table 2-23 for settings. |
9600 bps
EXEC
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 series, AGS, CGS, MGS | 50, 75, 110, 134, 150, 200, 300, 600, 1050, 1200, 2000, 2400, 4800, 9600, 19200, 38400 |
| 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 current auxiliary line transmit speed to 2400 bps:
terminal txspeed 2400
terminal rxspeed
terminal speed
To set the number of character columns on the terminal screen for the current line, use the terminal width EXEC command.
terminal width characters| characters | Number of character columns displayed on the terminal. |
80 character columns
EXEC
The width specified can be learned by remote hosts.
The following example sets the terminal character columns to 132:
terminal width 132
A dagger (+) indicates that the command is documented in another chapter.
width +
To display information about all open Telnet connections associated with the current terminal line, enter the where EXEC command at the system prompt.
whereThis command has no arguments or keywords.
EXEC
The following example shows output from the where command:
Router> where
Conn Host Address Byte Idle Conn Name
1 MIS1 131.108.19.50 0 0 MIS1
* 2 OTTER 192.31.7.24 0 0 OTTER
The information displayed includes the host name, address, number of characters waiting to be sent to the terminal, idle time, and connection name. An asterisk (*) indicates the current connection.
connect
name-connection
telnet (EXEC)
|
|