-
- Managing Configuration Files
- Configuration Generation Performance Enhancement
- Exclusive Configuration Change Access (Configuration Lock) and Access Session Locking
- Configuration Replace and Configuration Rollback
- Contextual Configuration Diff Utility
- Configuration Change Notification and Logging
- Configuration Logger Persistency
- Configuration Partitioning
- Finding Feature Information
- Contents
- Prerequisites for Configuring Operating Characteristics for Terminals
- Restrictions for Configuring Operating Characteristics for Terminals
- Information About Configuring Operating Characteristics for Terminals
- How to Configure Terminal Operating Characteristics
- Displaying Information About the Current Terminal Session
- Setting Local Terminal Parameters
- Saving Local Settings Between Sessions
- Ending a Session
- Globally Defining Escape Character and Other Key Sequences
- Defining Escape and Pause Characters for the Current Session
- Generating a Hardware Break Signal for a Reverse Telnet Connection
- Setting the Line to Refuse Full-Duplex, Remote Echo Connections
- Allowing Transmission Speed Negotiation
- Synchronizing the Break Signal
- Changing the End-of-Line Character
- Configuring Data Transparency for File Transfers
- Specifying the Character Display for All Lines
- Specifying the Character Display for a Line
- Specifying the Character Display for the Current Session
- Setting Character Padding
- Specifying the Terminal Type for a Line
- Specifying the Terminal and Keyboard Type for the Current Session
- Setting the Terminal Screen Length and Width for a Line
- Setting the Terminal Screen Length and Width for the Current Session
- Enabling Pending Output Notifications
- Setting Pending Output Notification for the Current Session
- Setting Character and Packet Dispatch Sequences for a Line
- Changing the Packet Dispatch Character for the Current Session
- Changing Flow Control for the Current Session
- Enabling Session Locking
- Configuring Automatic Baud Rate Detection
- Setting a Line as Insecure
- Configuring Communication Parameters for Terminal Ports
- Displaying Debug Messages on the Console and Terminals
- Recording the Serial Device Location
- Changing the Retry Interval for a Terminal Port Queue
- Configuring LPD Protocol Support on a Printer
- Displaying a List of Currently Defined Printers
Configuring Operating Characteristics for Terminals
Configuring the operating characteristics for terminals enables you to customize the settings for displays, formatting, and usability of the terminals on your network.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
•Prerequisites for Configuring Operating Characteristics for Terminals
•Restrictions for Configuring Operating Characteristics for Terminals
•Information About Configuring Operating Characteristics for Terminals
•How to Configure Terminal Operating Characteristics
Prerequisites for Configuring Operating Characteristics for Terminals
•You should have at least a basic familiarity with the Cisco IOS environment and the command-line interface.
•You should have at least a minimal configuration running on your system. You can create a basic configuration file using the setup command (see Using Setup Mode to Configure a Cisco Networking Device for details).
Restrictions for Configuring Operating Characteristics for Terminals
•Many of the Cisco IOS commands described in this document are available and function only in certain configuration modes on the router.
•Some of the Cisco IOS configuration commands are only available on certain router platforms, and the command syntax may vary on different platforms.
Information About Configuring Operating Characteristics for Terminals
•Definition of the Escape Character and Other Key Sequences
•Specification of an International Character Display
•Data Transparency for File Transfers
•Terminal Screen Length and Width
•Creation of Character and Packet Dispatch Sequences
•LPD Protocol Support on a Printer
Definition of the Escape Character and Other Key Sequences
Specification of an International Character Display
The classic U.S. ASCII character set is limited to 7 bits (128 characters), which adequately represents most displays in the U.S. Most defaults on the modem router work best on a 7-bit path. However, international character sets and special symbol display can require an 8-bit wide path and other handling.
You can use a 7-bit character set (such as ASCII), or you can enable a full 8-bit international character set (such as ISO 8859). This allows special graphical and international characters for use in banners and prompts, and adds special characters such as software flow control. Character settings can be configured globally, per line, or locally at the user level. Use the following criteria for determining which configuration mode to use when you set this international character display:
•If a large number of connected terminals support nondefault ASCII bit settings, use the global configuration commands.
•If only a few of the connected terminals support nondefault ASCII bit settings, use line configuration commands or the EXEC local terminal setting commands.
Note Setting the EXEC character width to an 8-bit character set can cause failures. If a user on a terminal that is sending parity enters the help command, an "unrecognized command" message appears because the system is reading all eight bits, although the eighth bit is not needed for help.
If you are using the autoselect function, the activation character should be set to the default Return, and the EXEC character bit should be set to 7. If you change these defaults, the application does not recognize the activation request.
Data Transparency for File Transfers
Data transparency enables the Cisco IOS software to pass data on a terminal connection without the data being interpreted as a control character.
During terminal operations, some characters are reserved for special functions. For example, the key combination Ctrl-Shift-6, X (^^x) suspends a session. When transferring files over a terminal connection (using the Xmodem or Kermit protocols, for example), you must suspend the recognition of these special characters to allow a file transfer. This process is called data transparency.
You can set a line to act as a transparent pipe so that programs such as Kermit, Xmodem, and CrossTalk can download a file across a terminal line. To temporarily configure a line to act as a transparent pipe for file transfers, use the terminal download command in EXEC mode. The terminal download command is equivalent to using all the following commands:
•terminal telnet transparent
•terminal no escape-character
•terminal no hold-character
•terminal no padding 0
•terminal no padding 128
•terminal parity none
•terminal databits
Terminal Screen Length and Width
By default, the Cisco IOS software provides a screen display of 24 lines by 80 characters. You can change these values if they do not meet the requirements of your terminal. The screen values you set are passed during rsh and rlogin sessions.
The screen values set can be learned by some host systems that use this type of information in terminal negotiation. To disable pausing between screens of output, set the screen length to 0.
The screen length specified can be learned by remote hosts. For example, the rlogin protocol uses the screen length to set terminal parameters on a remote UNIX host. The width specified also can be learned by remote hosts.
Creation of Character and Packet Dispatch Sequences
The Cisco IOS software supports dispatch sequences and TCP state machines that send data packets only when they receive a defined character or sequence of characters. You can configure dispatch characters that allow packets to be buffered, then sent upon receipt of a character. You can configure a state machine that allows packets to be buffered, then sent upon receipt of a sequence of characters. This feature enables packet transmission when the user presses a function key, which is typically defined as a sequence of characters, such as Esc I C.
TCP state machines can control TCP processes with a set of predefined character sequences. The current state of the device determines what happens next, given an expected character sequence. The state-machine commands configure the server to search for and recognize a particular sequence of characters, then cycle through a set of states. The user defines these states—up to eight states can be defined. (Think of each state as a task that the server performs based on the assigned configuration commands and the type of character sequences received.)
The Cisco IOS software supports user-specified state machines for determining whether data from an asynchronous port should be sent to the network. This functionality extends the concept of the dispatch character and allows the equivalent of multicharacter dispatch strings.
Up to eight states can be configured for the state machine. Data packets are buffered until the appropriate character or sequence triggers the transmission. Delay and timer metrics allow for more efficient use of system resources. Characters defined in the TCP state machine take precedence over those defined for a dispatch character.
LPD Protocol Support on a Printer
The Cisco IOS software supports a subset of the Berkeley UNIX Line Printer Daemon (LPD) protocol used to send print jobs between UNIX systems. This subset of the LPD protocol permits the following:
•Improved status information
•Cancellation of print jobs
•Confirmation of printing and automatic retry for common print failures
•Use of standard UNIX software
The Cisco implementation of LPD permits you to configure a printer to allow several types of data to be sent as print jobs (for example, PostScript or raw text).
How to Configure Terminal Operating Characteristics
To configure operating characteristics for terminals, perform any of the tasks described in the following sections. All tasks in this chapter are optional.
•Displaying Information About the Current Terminal Session
•Setting Local Terminal Parameters
•Saving Local Settings Between Sessions
•Globally Defining Escape Character and Other Key Sequences
•Defining Escape and Pause Characters for the Current Session
•Generating a Hardware Break Signal for a Reverse Telnet Connection
•Setting the Line to Refuse Full-Duplex, Remote Echo Connections
•Allowing Transmission Speed Negotiation
•Synchronizing the Break Signal
•Specifying the Terminal and Keyboard Type for the Current Session
•Changing the End-of-Line Character
•Configuring Data Transparency for File Transfers
•Specifying the Character Display for All Lines
•Specifying the Character Display for a Line
•Specifying the Character Display for the Current Session
•Specifying the Terminal Type for a Line
•Specifying the Terminal and Keyboard Type for the Current Session
•Setting the Terminal Screen Length and Width for a Line
•Setting the Terminal Screen Length and Width for the Current Session
•Enabling Pending Output Notifications
•Setting Pending Output Notification for the Current Session
•Setting Character and Packet Dispatch Sequences for a Line
•Changing the Packet Dispatch Character for the Current Session
•Changing Flow Control for the Current Session
•Configuring Automatic Baud Rate Detection
•Configuring Communication Parameters for Terminal Ports
•Displaying Debug Messages on the Console and Terminals
•Recording the Serial Device Location
•Changing the Retry Interval for a Terminal Port Queue
•Configuring LPD Protocol Support on a Printer
•Displaying a List of Currently Defined Printers
Displaying Information About the Current Terminal Session
To display terminal line information, complete the tasks in this section:
DETAILED STEPS
Examples
The following example shows sample output of the show whoami command:
Router> show whoami
Comm Server "Router", Line 0 at 0bps. Location "Second floor, West"
--More--
Router>
To prevent the information from disappearing from the screen, the show whoami command always displays a --More-- prompt before returning to the CLI prompt. Press the Spacebar to return to the prompt.
Setting Local Terminal Parameters
The terminal EXEC mode commands enable or disable features for the current session only. You can use these commands to temporarily change terminal line settings without changing the stored configuration file. To display a list of the commands for setting terminal parameters for the current session, complete the tasks in this section:
DETAILED STEPS
Examples
The following example shows sample output for the terminal ? command. Commands available on your routing device will vary depending on the software image and hardware you are using.
Router> terminal ?
autohangup Automatically hangup when last connection closes
data-character-bits Size of characters being handled
databits Set number of data bits per character
dispatch-character Define the dispatch character
dispatch-timeout Set the dispatch timer
download Put line into 'download' mode
editing Enable command line editing
escape-character Change the current line's escape character
exec-character-bits Size of characters to the command exec
flowcontrol Set the flow control
full-help Provide help to unprivileged user
help Description of the interactive help system
history Enable and control the command history function
hold-character Define the hold character
ip IP options
keymap-type Specify a keymap entry to use
lat DEC Local Area Transport (LAT) protocol-specific
configuration
length Set number of lines on a screen
no Negate a command or set its defaults
notify Inform users of output from concurrent sessions
padding Set padding for a specified output character
parity Set terminal parity
rxspeed Set the receive speed
special-character-bits Size of the escape (and other special) characters
speed Set the transmit and receive speeds
start-character Define the start character
stop-character Define the stop character
stopbits Set async line stop bits
telnet Telnet protocol-specific configuration
telnet-transparent Send a CR as a CR followed by a NULL instead of a CR
followed by a LF
terminal-type Set the terminal type
transport Define transport protocols for line
txspeed Set the transmit speeds
width Set width of the display terminal
Troubleshooting Tips
Many terminal settings can be configured for all terminal sessions or for just the current terminal session. Settings for all terminal sessions are configured in line configuration mode and can be saved. Settings for the current session are specified using EXEC mode commands that generally begin with the word terminal.
Saving Local Settings Between Sessions
To save local settings between sessions, complete the tasks in this section:
DETAILED STEPS
Troubleshooting Tips
If the private line configuration command is not used, user-set terminal parameters are cleared when the session ends with either the exit EXEC mode command or when the interval set with the exec-timeout line configuration command has passed.
Ending a Session
To end a session, complete the task in this section:
|
|
|
Step 1 |
quit Router> quit |
Ends the current session. |
DETAILED STEPS
What to Do Next
Refer to the "Managing Connections, Menus, and System Banners" chapter for more information on ending sessions and closing connections.
Globally Defining Escape Character and Other Key Sequences
To define or change the default key sequences involved with terminal session activation, disconnection, escape, or pausing, use the following commands in line configuration mode, as needed:
DETAILED STEPS
Troubleshooting Tips
For most of the commands described, you can reinstate the default value by using the no form. However, to return the escape character to its default, you should use the escape-character default line-configuration command.
Note If you are using the autoselect function (enabled using the autoselect line configuration command), the activation character should not be changed from the default value of Return. If you change this default, the autoselect feature may not function.
Defining Escape and Pause Characters for the Current Session
For the current terminal session, you can modify key sequences to execute functions for system escape and terminal pause. To modify these sequences, complete the tasks in this section:
DETAILED STEPS
Generating a Hardware Break Signal for a Reverse Telnet Connection
To cause the access server to generate a hardware Break signal on the EIA/TIA-232 line that is associated with a reverse Telnet connection for the current line and session, complete the task in this section.
Restrictions
The command in this section applies only to access servers.
DETAILED STEPS
Troubleshooting Tips
The hardware Break signal occurs when a Telnet Interrupt-Process 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:
•Several user Telnet programs send an Interrupt-Process command, but cannot send a Telnet Break signal.
•Some Telnet programs implement a Break signal that sends an Interrupt-Process command.
Some EIA/TIA-232 hardware devices use a hardware Break signal for various purposes. A hardware Break signal is generated when a Telnet Break command is received.
Setting the Line to Refuse Full-Duplex, Remote Echo Connections
To set the current line to refuse to negotiate full-duplex for the current session or remote echo options on incoming connections, complete the task in this section.
Restrictions
The command in this section applies only to access servers.
DETAILED STEPS
Allowing Transmission Speed Negotiation
To allow the Cisco IOS software to negotiate transmission speed for the current line and session, complete the task in this section.
Restrictions
The command in this section applies only to access servers.
DETAILED STEPS
Synchronizing the Break Signal
To cause the Cisco IOS software to send a Telnet Synchronize signal when it receives a Telnet Break signal on the current line and session, complete the task in this section.
Restrictions
The command in this section applies only to access servers.
DETAILED STEPS
Changing the End-of-Line Character
To cause the current terminal line to send a CR signal as a CR followed by a NULL instead of a CR followed by a line feed (LF), complete the task in this section.
Restrictions
The command in this section applies only to access servers.
DETAILED STEPS
Configuring Data Transparency for File Transfers
To temporarily configure a line to act as a transparent pipe for file transfers, complete the task in this section:
DETAILED STEPS
Specifying the Character Display for All Lines
To specify a character set for all lines (globally), complete steps 1, 2, and 3 or steps 1, 2, and 4 in this section:
DETAILED STEPS
Specifying the Character Display for a Line
To specify a character set based on hardware, software, or on a per-line basis, complete any of the tasks in this section:
DETAILED STEPS
Specifying the Character Display for the Current Session
To specify a character set based on hardware, software, or on a per-line basis for the current terminal session, use the following commands in EXEC mode:
DETAILED STEPS
Setting Character Padding
Character padding adds a number of null bytes to the end of a line and can be used to make that line an expected length for conformity. You can change the character padding on a specific output character.
Setting Character Padding for a Line
To set character padding for a line, complete the tasks in this section:
DETAILED STEPS
Changing Character Padding for the Current Session
To change character padding on a specific output character for the current session, complete the task in this section:
DETAILED STEPS
Specifying the Terminal Type for a Line
To specify the terminal type for a line, complete the tasks in this section:
DETAILED STEPS
Troubleshooting Tips
This feature is used by TN3270 terminals to identify the keymap and ttycap passed by the Telnet protocol to the end host.
Specifying the Terminal and Keyboard Type for the Current Session
To specify the type of terminal connected to the current line and keyboard type for the current session, complete the tasks in this section:
DETAILED STEPS
Setting the Terminal Screen Length and Width for a Line
To set the terminal screen length and width for all sessions on a line, use either of the following commands in line configuration mode:
DETAILED STEPS
Setting the Terminal Screen Length and Width for the Current Session
To set the number of lines or character columns on the current terminal screen for the current session, complete the tasks in this section:
DETAILED STEPS
Enabling Pending Output Notifications
To enable pending output notifications for a line, complete the tasks in this section:
DETAILED STEPS
Setting Pending Output Notification for the Current Session
To set pending output notification for the current session, complete the task in this section:
DETAILED STEPS
|
|
|
---|---|---|
Step 1 |
terminal notify Router> terminal notify |
Sets up a line to notify a user of pending output for the current session. |
Setting Character and Packet Dispatch Sequences for a Line
To configure your system, complete the tasks in this section:
DETAILED STEPS
Changing the Packet Dispatch Character for the Current Session
To change the packet dispatch character for the current session, complete the tasks in this section:
DETAILED STEPS
Changing Flow Control for the Current Session
To change flow control between the router and attached device for the current session, complete the tasks in this section, as needed:
DETAILED STEPS
Troubleshooting Tips
Software flowcontrol is enabled by default for EE switch console.
Enabling Session Locking
To allow session locking by users on a specific line or group of lines, complete the tasks in this section:
DETAILED STEPS
Configuring Automatic Baud Rate Detection
You can configure a line to automatically detect the baud rate being used. To set up automatic baud rate detection, complete the tasks in this section:
DETAILED STEPS
Troubleshooting Tips
To start communications using automatic baud detection, use multiple Returns at the terminal. A 600-, 1800-, or 19200-baud line requires three Returns to detect the baud rate. A line at any other baud rate requires only two Returns. If you use extra Returns after the baud rate is detected, the EXEC facility simply displays another system prompt.
Setting a Line as Insecure
You can set up a terminal line to appear as an insecure dialup line. The information is used by the local-area transport (LAT) software, which reports such dialup connections to remote systems.
To set a line as insecure, complete the tasks in this section:
DETAILED STEPS
Configuring Communication Parameters for Terminal Ports
To change the following parameters as necessary to meet the requirements of the terminal or host to which you are attached, complete the tasks in this section:
DETAILED STEPS
Displaying Debug Messages on the Console and Terminals
To display debug command output and system error messages in EXEC mode on the current terminal, complete the tasks in this section:
DETAILED STEPS
Troubleshooting Tips
Remember that all terminal parameter-setting commands are set locally and do not remain in effect after a session is ended. You must use this command at the privileged-level EXEC prompt at each session to display the debugging messages.
Recording the Serial Device Location
To record the location of a serial device so the text provided for the location appears in the output of the EXEC monitoring commands, complete the tasks in this section:
DETAILED STEPS
Changing the Retry Interval for a Terminal Port Queue
If you attempt to connect to a remote device such as a printer that is busy, the connection attempt is placed in a terminal port queue. If the retry interval is set too high, and several routers or other devices are connected to the remote device, your connection attempt can have long delays. To change the retry interval for a terminal port queue, complete the tasks in this section:
DETAILED STEPS
Configuring LPD Protocol Support on a Printer
To configure a printer for the LPD protocol, complete the tasks in this section:
DETAILED STEPS
Examples
The following example includes the configuration of the printer named saturn on the host memphis:
commlpt|Printer on cisco AccessServer:\
:rm=memphis:rp+saturn:\
:sd+/usr/spool/lpd/comm1pt:\
:lf=?var/log/lpd/commlpt:
The content of the actual file may differ, depending on the configuration of your UNIX system.
To print, users use the standard UNIX lpr command.
Troubleshooting Tips
If you use the printer command, you also must modify the /etc/printcap file on the UNIX system to include the definition of the remote printer on the router. Use the optional newline-convert keyword on UNIX systems that do not handle single character line terminators to convert a new line to a character Return, line-feed sequence.
Displaying a List of Currently Defined Printers
To display a list of currently defined printers and current usage statistics for each printer, complete the task in this section:
DETAILED STEPS
|
|
|
---|---|---|
Step 1 |
show printer Router> show printer |
Lists currently defined printers and their current usage statistics. |
Troubleshooting Tips
To provide access to LPD features, your system administrator must configure a printer and assign a TTY line (or lines) to the printer. The administrator must also modify the /etc/printcap file on your UNIX system to include the definition of the remote printer in the Cisco IOS software.