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This chapter explains how to configure lines and terminal settings. The LightStream 1010 ATM switch has two types of terminal lines: one console line and one auxiliary line. Most line setup is the same for all types of lines, but certain commands, such as those having to do with modem control and Serial Line Internet Protocol (SLIP)/Point-to-Point Protocol (PPP) support, apply to the auxiliary port only.
Note For a complete description of the commands mentioned in this chapter, refer to the LightStream 1010 ATM Switch Command Reference publication.
The following sections describe line configuration tasks. One of the first things you will need to do for line configuration is to set up the lines for the terminals or other asynchronous devices attached to them. The parameters for each line are configured next. However, the tasks you perform and the order in which you perform them are determined entirely by the requirements of your network environment.
Perform one or more of the tasks in the following sections to configure your LightStream 1010 line connections:
Line configuration mode is used to set the terminal-specific parameters. From line configuration mode, you can enter special commands called line configuration commands that affect the auxiliary or console port line you have specified. To enter line configuration mode, complete the following task:
| 1This command is documented in the LightStream 1010 ATM Switch Command Reference publication. |
For example, to configure line parameters for the auxiliary port at Step 2 in the preceding task, you would enter the following:
The auxiliary relative line number must be 0. See the modem line configuration commands in the section "Set Up Modem Control on the Auxiliary Port" later in this chapter to set up modem support on the auxiliary port.
The terminal from which you locally configure the LightStream 1010 ATM switch is attached to the console port. To configure line parameters for the console port at Step 2 in the preceding task, you would enter the following:
The console relative line number must be 0.
Configuring the console port or virtual terminal lines allows you to perform such tasks as setting communication parameters, specifying autobaud connections, and configuring terminal operating parameters for the terminal you are using. These tasks are described later in this chapter.
In the following example, the user creates and configures the maximum 4 virtual terminal lines with the "no login" feature:
In the following example, the user eliminates virtual terminal line number 4 and all higher-numbered virtual terminal lines. Only virtual terminal lines 0 to 3 will remain.
The LightStream 1010 ATM switch supplies default serial communication parameters for terminal and other serial device operation. You can change these parameters as necessary to meet the requirements of the terminal or host to which you are attached. To do so, perform one or more of the following tasks in line configuration mode:
| Task | Command |
|---|---|
Set the line speed. Choose from line speed, transmit speed, or receive speed. Speed applies to the auxiliary port only. |
|
The following example configures the auxiliary line with a speed of 19200 bit per second:
You can configure a terminal to automatically detect the baud rate being used over an asynchronous serial line. This command applies to the auxiliary port only. To set up automatic baud detection, perform the following task in line configuration mode:
To start communications using automatic baud detection, press Returns multiple times 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 press Return after the baud rate is detected, the EXEC simply displays another system prompt.
To change the default privilege level for a given line or a group of lines, perform the following task in line configuration mode:
| Task | Command |
|---|---|
| 1This command is documented in the LightStream 1010 ATM Switch Command Reference publication. |
On the auxiliary port, you can set both hardware and software flow control between the LightStream 1010 ATM switch and devices attached to it. Both types of flow control are bidirectional. When you specify software flow control, an additional keyword specifies the direction: in causes the LightStream 1010 ATM switch to listen to flow control from the attached device, and out causes the LightStream 1010 ATM switch to send flow control information to the attached device. If you do not specify a direction, the LightStream 1010 ATM switch enables software flow control in both directions.
For software flow control, the default stop and start characters are Ctrl-S and Ctrl-Q (XOFF and XON), respectively. However, you can define characters or character sequences that signal the start and end of data transmission when software flow control is in effect. This capability is useful for providing control of data over the serial line.
You can also specify hardware flow control. For information about setting up the RS-232 line, see the hardware installation and maintenance manual for your product.
To configure flow control between the LightStream 1010 ATM switch and attached device, perform one or more of the following tasks in line configuration mode:
You can set up a command that will automatically execute upon connection to another host. Any appropriate EXEC command and any switch or host name that occurs with the EXEC command is allowed. To do so, perform the following task in line configuration mode:
The LightStream 1010 ATM switch supports configuration of dispatch sequences. You can set up dispatch characters that allow packets to be buffered, then transmitted upon receipt of a character. These characters are useful on an auxiliary port only, and then only if you have some special-purpose device hooked up.
To configure a dispatch sequence, perform one or both of the following tasks as needed for your particular system in line configuration mode:
| Task | Command |
|---|---|
Define one or more characters that trigger packet transmission for a particular line. |
dispatch-character ascii-number1 |
You can selectively specify the protocols allowed on individual lines. You can set the protocol for incoming and outgoing connections and change the default (preferred) protocol for a line. The default transport protocol is Telnet.
Selecting which command to use is determined by whether it is for incoming or outgoing connections or is being used as a default (preferred) selection.
Perform one or more of the following tasks in line configuration mode to specify transport protocols:
The system accepts a host name entry at the EXEC system prompt as a Telnet command. If you mistype the host name, the system interprets the entry as an incorrect Telnet command and provides an error message indicating that the host does not exist. The transport preferred none command disables this option so that if you mistype a command at the EXEC prompt, the system will not attempt to make a Telnet connection.
You might need to control terminal sessions in high-traffic areas to provide resources for all users. You can define these limitations for terminal sessions:
To control terminal sessions, perform one or more of the following tasks in line configuration mode:
| Task | Command |
|---|---|
Warn users of impending timeouts set with the absolute-timeout command. |
Note The absolute-timeout command overrides any timeouts set through AppleTalk Remote Access (ARA) protocol.
You can configure modem control on the auxiliary port of the LightStream 1010 ATM switch. The auxiliary port is a standard RS-232-C DB-25 connector. Its output and input signals are listed in Table 3-1.
Table 3-1 Auxiliary Port Signals
| Pin | Signal | Direction | Description |
Configure modem control on the LightStream 1010 ATM switch performing the following tasks:
State diagrams accompany some of the tasks in the following sections to illustrate how the modem control works. The diagrams show two processes:
In the diagrams, the current signal state and the signal line is watching are listed inside each box. The state of the line (as displayed by the EXEC command show line) is listed next to the box. Events that change that state appear in italics along the event path, with the software actions described within the ovals.
Figure 3-1 illustrates line behavior when no modem control is set. The DTR output is always high, and CTS and RING are completely ignored. The LightStream 1010 ATM switch creates an EXEC when the user types the activation character. Incoming TCP connections occur instantly if the line is not in use and can be closed only by the remote host.
With the dial-up capability, you can set a modem to automatically dial the phone number of a remote LightStream 1010 ATM switch. This feature offers cost savings because phone line connections are made as needed. You only pay for using the phone line when there is data to be received or sent. To configure a line for automatic dialing, perform the following task in line configuration mode:
You can configure a line to close connections from a user's terminal when the terminal is turned off, and prevent inbound connections to devices that are out of service. To do so, perform the following task in line configuration mode:
Figure 3-2 illustrates the modem cts-required process. This form of modem control requires that CTS be high throughout the use of the line. If CTS is not high, the user's typed input is ignored and incoming connections are refused (or step to the next line in a rotary group).
Note In order for a LightStream 1010 ATM switch to reliably detect a CTS signal change, the signal must remain in the new state for at least one full second.
You can configure a line to automatically answer a modem. You would also configure the modem to answer the telephone on its own as long as DTR is high, drop connections when DTR is low, and use its Carrier Detect (CD) signal to accurately reflect the presence of carrier (configuring the modem is a modem-dependent process). Wire the modem's CD signal (generally pin-8) to the LightStream 1010 ATM switch's RING input (pin-22) and perform the following task in line configuration mode:
You can turn on the modem's hardware flow control independently to act on the status of the LightStream 1010 ATM switch's CTS input. Wire CTS to whatever signal the modem uses for hardware flow control. If the modem expects to control hardware flow in both directions, you might also need to wire the modem's flow control input to some other signal that the LightStream 1010 ATM switch always has high (such as DTR).
Figure 3-3 illustrates the modem ri-is-cd process. When the LightStream 1010 ATM switch detects a signal on the RING input of an idle line, it starts an EXEC or autobaud process on that line. If the RING signal disappears on an active line, the LightStream 1010 ATM switch closes any open network connections and terminates the EXEC. If the user exits the EXEC or the LightStream 1010 ATM switch terminates it because of no user input, the line hangs up the modem by lowering the DTR signal for five seconds. After five seconds, the modem is ready to accept another call.
The LightStream 1010 ATM switch supports dial-in modems that use DTR to control the off-hook status of the telephone line. Perform the following task in line configuration mode to configure the line to support this feature:
Figure 3-4 illustrates the modem callin process. When a modem dialing line is idle, it has DTR in a low state and waits for a transition to occur on the RING input. This transition causes the line to raise DTR and start watching the CTS signal from the modem. After the modem raises CTS, the LightStream 1010 ATM switch creates an EXEC on the line. If the timeout interval (set with the modem answer-timeout command) passes before the modem raises CTS, the line lowers DTR and returns to the idle state.
Note The modem callin and modem cts-required line configuration commands are useful for SLIP operation. These commands ensure that when the line is hung up or CTS drops, the line reverts from SLIP mode to normal interactive mode. These commands do not work if you use the async dedicated command to put the line in network mode permanently.
Although you can use the modem callin line configuration command with newer modems, the modem ri-is-cd line configuration command described earlier in this section is more appropriate. The modem ri-is-cd command frees up CTS for hardware flow control. Modern modems do not require the assertion of DTR to take a phone line off-hook.
The LightStream 1010 ATM switch supports ports connected to computers that are connected to modems. You can configure the LightStream 1010 ATM switch to behave somewhat like a modem by performing the following task in line configuration mode. This command also prevents incoming calls.
Figure 3-5 illustrates the modem callout process. When the LightStream 1010 ATM switch receives an incoming connection, it raises DTR and waits to see if the CTS becomes high as an indication that the host has noticed its signal. If the host does not respond within the interval set with the modem answer-timeout subcommand, the LightStream 1010 ATM switch lowers DTR and drops the connection.
You can configure a line for both incoming and outgoing calls by performing the following task in line configuration mode:
Figure 3-6 illustrates the modem in-out process. If the line is activated by raising RING, it behaves exactly as a line configured with the modem ri-is-cd subcommand described earlier. If the line is activated by an incoming TCP connection, the line behaves similarly to a nonmodem line.
Note If your system incorporates dial-out modems, consider using access lists to prevent unauthorized use.
You can change the interval that the LightStream 1010 ATM switch waits for CTS after raising DTR in response to RING from the default of 15 seconds. To do so, perform the following task in line configuration mode. The timeout applies to the modem callin command only.
Connections can be made to the next free line in a group of lines, also called a rotary or hunt group. A line can be in only one rotary group; a rotary group can consist of a single line or several contiguous lines. The console line (line 0) cannot be in a rotary group.
You might want to assign the rotary with the single auxiliary port line, because the auxiliary port is not necessarily the same line number on all hardware. By putting it in a rotary group, you do not have to track the actual line number. Another reason to use a rotary group is that if the device supports local area transport (LAT), an inbound service can only be bound to a rotary group; it cannot be bound to a port number.
To configure a rotary group, perform the following task in line configuration mode:
You can configure automatic line disconnect by performing the following task in line configuration mode:
The command causes the EXEC to issue the exit command when the last connection closes. This feature is useful for UNIX-to-UNIX Copy Program (UUCP) applications that require this behavior, because UUCP scripts cannot issue the command that hangs up the telephone.
Dial-up modems that operate over normal dial-up telephone lines at speeds of 9600 bits per second (bps) and higher are now available. These modems do not operate at a guaranteed throughput; instead, they operate at a speed dependent on the quality of the line, the effectiveness of data compression algorithms on the data being transmitted, and other variables. These modems use hardware flow control to stop the data from reaching the host by toggling an RS-232 signal when they cannot accept any more.
In addition to hardware flow control, dial-up modems require special software handling. For example, they must be configured to create an EXEC when a user dials in and to hang up when the user exits the EXEC. These modems must also be configured to close any existing network connections if the telephone line hangs up in the middle of a session.
Your LightStream 1010 ATM switch supports hardware flow control on its CTS input, which is also used by the normal modem handshake.
Perform the following tasks to configure and use a high-speed modem:
| 1This command is documented in the LightStream 1010 ATM Switch Command Reference publication. |
Chat scripts are strings of text used to send commands for modem dialing, logging onto remote systems, and initializing asynchronous devices connected to the line. On a LightStream 1010 ATM switch, chat scripts can be configured on the auxiliary port only. A chat script must be defined for dialing out on asynchronous lines.
You can configure chat scripts manually, or you can configure a line to activate a chat script in response to one of the following events on a line:
To use a chat script, perform the following steps:
Step 2 Configure the line so that a chat script is activated when a specific event occurs, or start a chat script manually.
To define a chat script, perform the following task in global configuration mode:
| Task | Command |
|---|---|
Create a script that will place a call on a modem, log on to a remote system, or initialize an asynchronous device on a line. |
| 1This command is documented in the LightStream 1010 ATM Switch Command Reference publication. |
A limited list of keywords is supported along with expect/send pairs. Send strings can have special escape modifiers.
We recommend that you write two chat scripts: one modem chat script for placing a call and another system or login chat script to log on to remote systems, where required.
When you create a script name, include the modem vendor, type, and modulation separated by hyphens (-). For example, if you have a Telebit t3000 modem that uses V.32bis modulation, your script name would be telebit-t3000-v32bis.
Chat scripts can be activated by any of five events, each corresponding to a different version of the script line configuration command. To start a chat script manually at any point, refer to the section "Start a Chat Script Manually."
To define a chat script to start automatically when a specific event occurs, perform the following tasks in line configuration mode:
| 1The argument regexp is a regular expression matched to a script name that has already been defined with the chat-script command. |
You can start a chat script manually on any line that is currently not active by performing the following task in privileged EXEC mode:
| Task | Command |
|---|---|
If you do not specify the line number, the script runs on the current line. If the line specified is already in use, you cannot start the chat script. A message appears indicating that the line is already in use.
We support 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 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).
To configure a printer for the LPD protocol, perform the following task in global configuration mode:
| Task | Command |
|---|---|
Configure printer and specify a tty line (or lines) for the device. |
printer printername {line number | rotary number} [newline-convert] |
If you use the printer command, you will also have to modify the /etc/printcap file on the UNIX system to include the definition of the remote printer on the access server. Use the optional newline-convert keyword on UNIX systems that do not handle single character line terminators to convert a new line to a carriage-return, linefeed sequence.
The following example includes the configuration of the printer Saturn on the host Memphis:
The content of the actual file may differ depending on the configuration of your system.
In addition to initiating connections, the LightStream 1010 ATM switch can receive incoming connections on the auxiliary port. This capability allows you to attach serial printers, modems, and other shared peripherals to the LightStream 1010 ATM switch and drive them remotely from other systems. The LightStream 1010 ATM switch supports reverse TCP connections.
The specific TCP port or socket to which you attach the peripheral device determines the type of service the LightStream 1010 ATM switch provides on that line. When you attach the serial lines of a computer system or a data terminal switch to the auxiliary port of the LightStream 1010 ATM switch, the LightStream 1010 ATM switch acts as a network front end for a host that does not support the TCP/IP protocols. This arrangement is sometimes called front-ending or reverse connection mode.
To connect the auxiliary port, the remote host or terminal must specify a particular TCP port on the LightStream 1010 ATM switch. If Telnet protocols are required, that port is 2000 (decimal) plus the decimal value of the line number.
If a raw TCP stream is required, the port is 4000 (decimal) plus the decimal line number. The raw TCP stream is usually the required mode for sending data to a printer.
The Telnet protocol requires that carriage return characters be translated into carriage return and linefeed character pairs. You can turn this translation off by specifying the Telnet binary mode option. To specify this option, connect to port 6000 (decimal) plus the decimal line number.
In line configuration mode, you can set terminal operation characteristics that will be in operation for that line until the next time you change the line parameters.
Alternatively, you can temporarily change the line settings with the terminal EXEC commands provided in the chapter "Understanding the User Interfaces for the LightStream 1010 ATM Switch."
Define the terminal operation characteristics by performing the following tasks:
You can specify the type of terminal connected to a line. This feature has two benefits: it provides a record of the type of terminal attached to a line, and it can be used in Telnet terminal negotiations to inform the remote host of the terminal type for display management. To specify the terminal type, perform the following task in line configuration mode:
By default, the LightStream 1010 ATM switch provides a screen display of 24 lines by 80 characters. You can reconfigure these values if they do not meet the needs of your terminal by performing the following tasks in line configuration mode:
The values set can be learned by some host systems that use this type of information in terminal negotiation. Set a value of zero for the screen length to disable pausing between screens of output.
You can define or modify the default key sequences to execute functions for system escape, terminal activation, disconnect, and terminal pause. To define or change the default sequence, perform one or more of the following tasks in line configuration mode:
You can reinstate the default value for the escape character or activation character by using the no form of the command. For example, issuing the no escape-character line configuration command returns the escape character to Ctrl-^.
Note If you are using the autoselect command, do not change the activation character from the default value of Return. If you change this default, autoselect may not function immediately.
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) to allow special graphical and international characters for use in banners and prompts, and to add special characters such as software flow control. These settings can be configured globally by interface or locally at the user level. Use the following criteria for determining the configuration mode to use to set up this feature:
Note Setting the EXEC character width to 8 bits can cause failures. If a user on a terminal that is sending parity enters the command help, an unrecognized command message appears because the system is reading all eight bits, although the eighth bit is not needed for the help command.
To specify a character set on a global basis, perform one or both of the following tasks in global configuration mode:
To specify a character set based on hardware or software, or on a per-line basis, perform the appropriate task in line configuration mode, as follows:
Note If you are using the autoselect function, let the activation character default to Return, and exec-character-bits default to 7. If you change these defaults, the application will not recognize the activation request.
You can change the character padding on a specific output character. Character padding adds a number of null bytes to the end of the string and can be used to make a string an expected length for conformity. To set character padding, perform the following task in line configuration mode:
To disable enhanced editing mode and revert to the editing mode of previous software releases, perform the following task in line configuration mode:
| Task | Command |
|---|---|
Disable the enhanced editing features for a particular line. |
| 1This command is documented in the LightStream 1010 ATM Switch Command Reference publication. |
You might disable enhanced editing if you have prebuilt scripts, for example, that do not interact well when enhanced editing is enabled. You can reenable enhanced editing mode with the editing command.
You can enable a terminal-locking mechanism that allows a terminal to be temporarily locked by performing the following task in global configuration mode:
After you configure the line as lockable, you must still issue the lock EXEC command to lock the keyboard.
By default, user-set terminal parameters are cleared with the EXEC command exit or when the interval set with the exec-timeout line configuration command has passed. However, you can configure a line so that user-set terminal parameters are saved between sessions by performing the following task in line configuration mode:
| Task | Command |
|---|---|
Configure a line so that the terminal parameters the user sets remain in effect between terminal sessions. |
You can provide the host name, line number, and location each time an EXEC is started or an incoming connection is made. The line number banner appears immediately after the EXEC banner or incoming banner. It is useful for tracking problems with modems because it lists the host and line for the modem connection. Modem information is also included if applicable.
To provide service line number information, perform the following task in global configuration mode:
You can enable password checking on a particular line so that the user is prompted to enter a password at the system login screen. You must then also specify a password. Perform the following tasks in line configuration mode:
| Task | Command |
|---|---|
| Step 1. Enable password checking on a per-line basis using the password specified with the password command. | |
| Step 2. Assign a password to a particular line. |
You can enable password checking on a per-user basis, in which case authentication is based on the username specified with the username global configuration command, as described in the "Configuring System Management Functions" chapter. To enable this type of password checking, perform one of the following tasks in line configuration mode:
Use the login tacacs command with TACACS and extended TACACS. Use the login authentication command with AAA/TACACS+.
By default, virtual terminals require passwords. If you do not set a password for a virtual terminal, it responds to attempted connections by displaying an error message and closing the connection. Use the no login command to disable this behavior and allow connections without a password.
For other access control tasks and password restrictions, including the enable password global configuration command that restricts access to privileged mode, see the "Configuring System Management Functions" chapter.
The following example shows password checking enabled for a virtual terminal line 1:
The following example shows password checking enabled on a user basis:
The LightStream 1010 ATM switch supports configuration of dispatch sequences. You can set up dispatch characters that allow packets to be buffered, then transmitted upon receipt of a character. These characters are useful on an auxiliary port only, and then only if you have some special-purpose device hooked up.
Perform the following tasks in line configuration mode, as required for your particular system needs:
| Task | Command |
|---|---|
Define one or more characters that trigger packet transmission for the current terminal session. |
dispatch-character ascii-number1 [ascii-number2 . . . ascii-number] |
To configure the LightStream 1010 ATM switch to allow an AppleTalk Remote Access (ARA), PPP, or SLIP session to start automatically, perform the following task in line configuration mode:
The autoselect command enables the LightStream 1010 ATM switch to start an appropriate process automatically when it receives a starting character. The LightStream 1010 ATM switch detects either a Return character, which is the start character for an EXEC session, or the start character for the ARA protocol. Using the optional during login argument enables the user to receive the username or password prompt without pressing the Return key. While the username or password is presented, you can choose to answer these prompts or to start sending packets from an autoselected protocol. Refer to the end of this chapter for configuration examples.
Note When using autoselect, let the activation character default to Return, and exec-character-bits default to 7. If you change these defaults, the application does not recognize the activation request.
Configure the following types of messages that will be displayed to users of terminals connected to the LightStream 1010 ATM switch by performing one or more of the following tasks:
The following sections explain how to configure these messages and how to suppress display of the message-of-the-day (MOTD) and line activation banners.
You can configure a message of the day (MOTD) to be displayed on all connected terminals. This message is displayed at login and is useful for sending messages that affect all network users, such as impending system shutdowns. To do so, perform the following task in global configuration mode:
You can configure a line activation message to be displayed when an EXEC process such as line activation or an incoming connection to a virtual terminal is created. To do so, perform the following task in global configuration mode:
You can configure a message to be displayed on terminals connected to reverse Telnet lines. This message is useful for providing instructions to users of these types of connections. Reverse Telnet connections are described in more detail in the section "Support Reverse TCP Connections" earlier in this chapter.
To configure the message that will be sent on incoming connections, perform the following task in global configuration mode:
You can configure messages to be displayed on a console or terminal not in use. Also called a vacant message, this message is different from the banner message displayed when an EXEC process is activated. To configure an idle terminal message, perform the following task in line configuration mode:
You can control display of the MOTD and line activation banners. By default, these banners are displayed on all lines. To suppress or reinstate the display of such messages, perform one of the following tasks in line configuration mode:
| Task | Command |
|---|---|
Suppose you want a message explaining that the server is going to be reloaded with new software. The following example shows how to use the banner global configuration command and
no exec-banner line configuration command to notify your users:
Telnet is a virtual terminal protocol that is part of the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol suite that allows connections to hosts. You can configure a line to support the Telnet capabilities using one or more of the procedures described in the following sections:
A hardware Break signal is generated when a Telnet Break command is received. You can configure the LightStream 1010 ATM switch to also generate a Break on Interrupt Process command. To enable the system to generate a hardware Break signal on the RS-232 line that is associated with a reverse Telnet connection, complete the following task in line configuration mode:
This capability is useful because several user Telnet programs can send an Interrupt Process command but cannot send a Telnet Break signal, while other programs implement a Break signal that sends an Interrupt Process command. RS-232 devices use the hardware Break signal for various purposes.
You can cause Telnet to refuse to negotiate full-duplex, remote echo options on incoming connections. Use the following command on reverse Telnet connections to allow the LightStream 1010 ATM switch to refuse these requests from the other end. This command suppresses negotiation of the Telnet Remote Echo and Suppress Go-Ahead options. Perform the following task in line configuration mode:
To allow the line to negotiate a bit rate on incoming connections, perform the following task in line configuration mode:
| Task | Command |
|---|---|
The LightStream 1010 ATM switch uses the default speed if the connected device does not specify a speed. The maximum speed is the highest speed the LightStream 1010 ATM switch uses.
To cause an incoming connection to send a Telnet synchronize signal when it receives a Telnet Break signal, complete the following task in line configuration mode:
| Task | Command |
|---|---|
Cause an incoming connection to send a Telnet synchronize signal when it receives a Telnet Break signal. |
This capability is used very rarely to ensure the ordering of Break reception with respect to data characters sent after the Break signal.
To configure the LightStream 1010 ATM switch to send a carriage return (CR) as a CR followed by a NULL instead of a CR followed by a line feed (LF), complete the following task in line configuration mode:
This capability is useful for coping with different interpretations of end-of-line handling in the Telnet protocol specification.
You can define a message that is displayed when a Telnet connection to a specified host fails or succeeds. To do so, perform one or both of the following tasks in global configuration mode:
With the login-string options, you can set a pause, prevent a user from issuing commands during a pause, send a Break character, and use a percent sign (%) in the login string.
You can record the location of a serial device by performing the following task in line configuration mode. The text provided for the location appears in the output of the EXEC monitoring commands.
You can set up a line to inform a user who has multiple, concurrent Telnet connections when output is pending on a connection other than the current one. To do so, perform the following task in line configuration mode:
YOu can create a message that says the line is in use by performing the following task in line configuration mode:
By default, the LightStream 1010 ATM switch starts an EXEC process on all lines; however, commands are available to control EXEC processes, as follows:
When you want to allow an outgoing connection only for a line, use the no exec command. When you try to use a line with the EXEC off, you will get no response when pressing the Return key at the login screen.
The EXEC command interpreter waits for a specified interval of time until you begin input. If no input is detected, the EXEC resumes the current connection. If no connections exist, the EXEC returns the terminal to the idle state and disconnects the incoming session.
To control the EXEC as stated above, perform the following tasks in line configuration mode:
| Task | Command |
|---|---|
The following example configures virtual terminal line number 0 with an executive timeout of 5 minutes:
The EXEC provides the ability to display debug command output and system error messages on the current terminal. To enable this feature, perform the following task in EXEC mode:
| Task | Command |
|---|---|
Display debug command output and system error messages on the current terminal. |
| 1This command is documented in the LightStream 1010 ATM Switch Command Reference. |
Refer to the LightStream 1010 ATM Switch Debug Command Reference publication for details on debug commands and output.
Posted: Thu Jan 23 21:03:25 PST 2003
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