VTY Line Configuration for Telnet Access

Virtual terminal lines are used to allow remote access to a router. The router has five virtual terminal lines, by default. You will configure the five vty lines (vty 0 through 4) for Telnet access and set a password on these lines. In addition, you want to ensure that, after 15 minutes of inactivity on the vty lines, the connection times out. To configure the vty lines, you will do the following from global configuration mode:

Device configuration :

RouterINB#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

RouterINB (config)#line vty 0 4

RouterINB (config-line)#

You can verify that you have successfully entered line configuration mode because the prompt has changed, as shown in above config.. Next, enable login on the vty lines and set a Telnet password of INBSecret on RouterINB.

Configure vty Lines with Login and Password Checking

RouterINB (config-line)#login

RouterINB (config-line)#password INBSecret

Notes:

Remember that if an enable password has not been set on the router, you cannot Telnet into the router. This is true even when a password has been set on the vty lines. Although not shown here, assume that the terminal server has been configured with the enable password INBSecret.

Finally, it is a good idea to set timeout values on your vty lines so that idle Telnet sessions will not remain up indefinitely. By default, the exec-timeout is set to 10 minutes on both the console and the vty ports.

The timeout value is specified in minutes and seconds. You will set the timeout value to 15 minutes and 0 seconds on vty lines 0 through 4 using the exec-timeout command.

Setting the exec-timeout Value to 15 Minutes and 0 Seconds on vty Lines 0 Through 4

RouterINB (config-line)#exec-timeout ?

 <0-35791> Timeout in minutes

RouterINB (config-line)#exec-timeout 15 ?

 <0-2147483> Timeout in seconds

 <cr>

RouterINB (config-line)#exec-timeout 15 0

RouterINB (config-line)#

Verify the configuration changes in your running-config by exiting back to privileged EXEC with CTRL-Z and then using a show running-config command. The highlighted section of Example 4-8 shows the last portion of the running-config with the configuration of the five vty lines.

Verify Changes with show running-config Command

RouterINB (config-line)#^Z

RouterINB #show running-config

line con 0

 login

line 1 16

line aux 0

line vty 0 4

 exec-timeout 15 0

 password 7 15140A0007252537

 login

The end of the config shows all lines on the router, as well as the changes you have made to the vty lines.

Saving the Running Configuration

Save the configuration by typing copy running-config startup-config from global configuration mode,

Copy running-config to startup-config

RouterINB #copy running-config startup-config

Building configuration…

[OK]

RouterINB #