You are done using the router and want to log out so that no one can sit down at your terminal and access the router.
Log out of the router:
aviva@router1> exit [server1.mycompany.com] aviva@server%
One of the simplest and most obvious ways to protect the security of the router is to log out when you have no reason to be logged in or when you have to step away from your terminal for a few minutes. You must be in operational mode to log out. If you are in configuration mode, exit from it first:
 aviva@router1# exit aviva@router1> exit aviva@server1%
When you are not at the top level of configuration mode, you can go there before exiting:
[edit snmp v3 vacm] aviva@router1# top  aviva@router1# exit aviva@router1> exit aviva@server1%
You can also exit directly from a lower level in the hierarchy:
[edit snmp v3 vacm] aviva@router1# exit configuration-mode aviva@router1> exit aviva@server1%
By default, a user can remain logged in to the router for an unlimited amount of time when your login session is idle. You can limit the time by setting an idle timeout value for each login privilege class (see Recipe 2.10).
Router Configuration and File Management
Basic Router Security and Access Control
Routing Policy and Firewall Filters