How to set default session timeout in Linux

My DC operation guys access Linux servers on a daily basis but somehow they never remember to log out. This is a security risk as anyone could gain access to the open console and create caos.

Today, yet again I’m forced to play the bad guy by dummy proofing my Linux servers by implementing default timeout for user sessions.

Bash and Korn both support the TMOUT variable which I will use to set the default timeout.

The etc/.bashrc file will apply the timeout system wide but if you need it to be user specific then modify the ~/.bashrc file instead.

Here’s how it’s done.

echo "TMOUT=300 >> /etc/bashrc

echo "readonly TMOUT" >> /etc/bashrc

echo "export TMOUT" >> /etc/bashrc

Log off, start a new session and wait for 5 minutes. Your session should terminate

6 Responses to “How to set default session timeout in Linux”

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1. Manojg says:

   April 29, 2008 at 9:00 pm

   This is helpful. what is the equivalent variable for c shell? I connect to the remote computer via ssh and I am being log out after certain time if I stop working. I checked the /etc/bashrc and /etc/csh.cshrc files in remote computer, and ~.bashrc and ~.cshrc files in my local computer but I could not find anything about the log out time. Where is this log out time hidden?

   Thanks.

   Reply
2. Shrirang says:

   October 16, 2008 at 2:37 am

   Danesh,

   Does the soultion work if someone enables the keepalive configuration in the client application (like putty)? It will not, since the client will keep sending null packets to the server, so it will never seem like the client is idle.

   Thanks,

   Shrirang.

   Reply
3. Chris says:

   June 4, 2010 at 1:56 am

   If you’re running debian check out timeoutd. Not sure if it will solve all your issues but it sure is nice to have that in one place.

   Reply
4. vaibhav says:

   June 4, 2010 at 8:47 pm

   Is it possible to set different timeouts for different users?

   I mean I do not want user1 to be idle for more than, say, 5 minutes, but it is alright if user2 stays idle for an hour or so.

   Is it possible to execute it?

   Reply
5. Danesh says:

   June 6, 2010 at 2:56 am

   vaibhav, you could try adding the above into the .bashrc file within your user’s user dir.

   Tell me if it works

   Reply
6. LinuxM@n says:

   January 17, 2012 at 1:29 am

   Thanks for posting the timeout instructions. I work with Ubuntu 10.04 and the 3 lines of code does in fact disconnect my user.

   I modified the .bashrc file in the home directory.

   Thanks!

   Reply