Difference between 'session-timeout' and 'exec-timeout'

[n_khanolkar]

I wanted to know the difference between the mechanisms of 'session-timeout' and 'exec-timeout' command. I tried to check out the Cisco website but couldn't find a comprehensive answer to the same. Can anybody help me out?

[Kevin Dorrell]

Nishant,

There are several things you can use the vty lines for, including terminal server sessions, PAD, etc. One of those many applications is to get into the executive of the router itself, i.e. the CLI.

I believe that "session-timeout" applies to all sessions going through the vty port for all the various applications. "exec-timeout" applies specifically to sessions that are connected to the exec of the router itself. An exec timeout is triggered by the exec itself.

Now, I know you are asking why did your session-timeout kick out your connection, but failed to release your exec so that the next session can use it. Whereas "exec-timeout works correctly. Surely disconnecting the session should have released the exec. I'll have to admit that I don't know to that one either!

When you find out, please let us know!

Kevin Dorrell

Luxembourg.

[n_khanolkar]

Precisely Kevin!! Actually I want to understand whether the relationship between a session and EXEC is a parent-child one or then there are 2 independent processes which have no control over each other.

This is pertaining to the last case which I put up and you had speculated the probable theory of session disconnecting but the router not releasing the 'EXEC'. Even I am puzzled by this query and hence want to prod a bit deeper to understand the mechanisms of telnet and the CLI processes and their relationships.

I hope our other pardners on the group could help out!?

[makchitale]

exec-timeout - is the amount time from the console or telnet session to the router that the router will allow traffic. After the time has been reached it will disconnect the connection. To prevent this problem set the "exec-timeout" 0 0

session-timeout- is the idle time set for a session thru the router. If the idle time has been reached the session will be disconnected.

In order words, A session timeout applies to a user who has logged into the router (on tty/ vty) then started a "session" of some sort, like "telnet server1". If the user sits idle at server1 for the session timeout period user will get kicked back to the router prompt.

An exec-timeout applies to how long user can sit idle at the router prompt.

Thanks, Mak

[n_khanolkar]

Thanx Mak,

That explanation will certainly help understand the terms in relevance to my problem.

Regards,

Nishant.

[vcjones]

Just a quick hint to any lurkers: setting exec-timeout to 0 0 is fine for a lab setup but not good for production use. You want the router to automatically drop unused connections (such as those from systems which have gone away without logging off) or you will find that you will no longer be able to log into the router because all VTYs are "in use."

Instead, set the exec-timeout to something long enough to avoid being inconvenienced, such as 600 0 (ten hours). More than enough to keep you from being logged off, but short enough so that everything gets cleaned up over night.

Been there, done that, been burnt!

Vincent C Jones

www.networkingunlimited.com