Comments on: ssh keep-alive tip

By: Trevor

Trevor — Tue, 21 Feb 2012 22:21:36 +0000

Brilliant Cam, thanks for the tip

By: Alejandro Pisanty

Alejandro Pisanty — Sun, 08 Jan 2012 17:44:32 +0000

Screen plus the clock device worked best for me. I can keep a perfectly decent interface (email) with but minor glitches. Use the -O option in screen – it will optimize the output for your type of terminal instead of forcing strict VTx. Also, you may need to resize the window to fully accomodate changes. Thanks to all contributors!

One more note: I hadn’t needed this until now; my ISP improved services seriously by introducing FTTH, but their core equipment is giving timeouts to either SSH or port 22 (we don’t know which for sure yet) after painfully short inactivity times. I’ve seen this in a few other networks as well.

By: AndresVia

AndresVia — Sun, 04 Dec 2011 23:26:44 +0000

@Adam Reed would you please explain your piece of ksh code.

By: Bob

Bob — Tue, 11 Oct 2011 08:20:23 +0000

Where’s the “like” button

By: Michael C

Michael C — Sat, 09 Jul 2011 17:11:55 +0000

Very interesting. I’m in Canada (just got here recently) and have noticed the same behavior. Back in the U.S., I could keep an idle connection open indefinitely (weeks, months, etc.), whereas here I return to my terminal and see closed connections if I leave my machine for a bit (haven’t tested to see exactly how long, but it seems quite short, definitely under an hour). I blame my either my ISP (TekSavvy) or its cable provider (Rogers). It’s downright wrong to close people’s TCP connections just because you feel like it. What if I were streaming something from a server and the server had a hiccup and stopped streaming for some time: are they going to close that connection, too, and force me to restart the entire stream just because they feel like it? Canada is weird in this respect. Whether it’s due to bureaucracy or incompetence, it doesn’t matter, it just plain sucks and makes no sense at all.

By: juan

juan — Wed, 01 Dec 2010 17:42:35 +0000

how can i implement a windows/apache/php web site to keep track of unix servers, using some sort of keep alive.. I m currently using a ping but i find that a bit slow if you have multiple servers is there another low level tool/utility i can use to check on server availability?

By: Aaron

Aaron — Mon, 01 Nov 2010 15:37:52 +0000

I’m guessing that no one here has tried:

export TMOUT=0 in their ~/.bash_profile? It works with our stringent security policies on our RHEL5 machines. No need to send a loop to the background.

while date; sleep 5; done > /dev/null

Would work better than the poster’s loop anyway, you wouldn’t need crap printed to the screen, and it is registered as “activity”.

By: Joe Blow

Joe Blow — Wed, 13 Oct 2010 01:17:42 +0000

The correct syntax for setting the ssh TCPKeepAlive option is:

ssh -o TCPKeepAlive=yes mark@localhost

i.e., you must include the "=yes" value after the TCPKeepAlive identifier! All the Best, Joe Mark says: January 16, 2007 at 1504 UTC

or you could just do a
ssh -o TCPKeepAlive mark@localhost
which will do the same and handy if bouncing between boxes.