Sometimes we want to change any parameter of our current user interface quickly, let’s say terminal length or idle timeout, but we don’t know which user interface we are currently using. To check that we use display user-interface command. Then we try to find the “+” mark in the command output, which means that this is our current user interface. After that we have to go back to our user interface configuration and change its parameters. Why not to do that in a quicker manner?
[labnario]display user-interface Idx Type Tx/Rx Modem Privi ActualPrivi Auth Int 0 CON 0 9600 - 15 - P - 33 AUX 0 9600 - 0 - P - + 34 VTY 0 - 0 3 A - + 34 VTY 0 - 0 3 A - 35 VTY 1 - 0 - A - 36 VTY 2 - 0 - A - 37 VTY 3 - 0 - A - 38 VTY 4 - 0 - A - 50 VTY 16 - 15 - A - 51 VTY 17 - 15 - A - 52 VTY 18 - 15 - A - 53 VTY 19 - 15 - A - 54 VTY 20 - 15 - A - UI(s) not in async mode -or- with no hardware support: 1-32 + : Current UI is active. F : Current UI is active and work in async mode. Idx : Absolute index of UIs. Type : Type and relative index of UIs. Privi: The privilege of UIs. ActualPrivi: The actual privilege of user-interface. Auth : The authentication mode of UIs. A: Authenticate use AAA. N: Current UI need not authentication. P: Authenticate use current UI's password. Int : The physical location of UIs.
In case we want to change any parameter of our current user terminal interface, without checking which user interface we are using, “current” option for the user-interface command can be used.
Let’s look at VTY configuration:
[labnario]dis current-configuration configuration user-interface # user-interface vty 0 4 authentication-mode aaa idle-timeout 15 0 protocol inbound ssh
Now we can change configuration of current user-interface:
[labnario]user-interface current [labnario-ui-vty0]screen-length 0 [labnario-ui-vty0]idle-timeout 20 0 [labnario-ui-vty0]dis this # user-interface vty 0 authentication-mode aaa idle-timeout 20 0 screen-length 0 protocol inbound ssh user-interface vty 1 4 authentication-mode aaa idle-timeout 15 0 screen-length 40 protocol inbound ssh