What they are, and why they’re so, so important (and useful).
Let’s say you need to make a routing change on a remote switch, and won’t be able to have anyone physically access it should something go wrong…this is when config session timers come into play!
Create a new configure session
To enter a new session, instead of just entering the config prompt with # config, enter:
# config session $NAME
You’ll be placed into a session where you can make as many configuration changes as needed, but none of them will apply until you commit the session.
Commit a session, with a timer
Once you have a new config created, use this command while still in the session to commit it, with a failsafe timer:
commit timer HH:MM:SS
Once you press RETURN, your commit will go live until the end of that timer or until you abort, whichever comes first.
Active commit session commands
Assuming your commit isn’t catastrophic and removes your ability to access the switch, you have two options to manipulate the session: abort, and commit early.
Abort!
If while the commit timer is still running you decide to roll back, use
configure session $SESSIONNAME abort
from en EXEC command prompt to abort the session and roll back to the previous config.
Commit early!
If the new config is good, and you want to actually write it to the startup configuration, enter
configuration session $SESSIONNAME commit
to commit the running candidate config to memory.
Check the status of a commit
If you have multiple sessions in progress or want to see the time remaining on a commit session, use
show configuration session detail
to view all current sessions.
NOTE: If you’re running CVP you’ll also see that active session…that’s expected!