ssh connections now freezing, if left idle for a few minutes

[Cameron Simpson]

On 21Oct2015 09:20, Tom Horsley <horsley1953 at gmail.com> wrote:
>On Wed, 21 Oct 2015 12:19:55 +1100
>Cameron Simpson wrote:
>> Is your connection essentially for purposes of port forwards?
>
>Yep. My script has also evolved over time and may be similar.
>
>I saw some very strange behavior sometimes though where it acted
>like the connection was busted only in one direction. I could forward
>from work to home, but not the other way (or from home to work
>depending on which direction broke :-). This is how I eventually
>evolved to doing the periodic ssh-keyscan in both directions to
>make sure it still worked both ways.

One thing to keep in mind is that if you're running a reverse port forward 
(from the remote system back to a local service) and your local client end has 
quit but the server side has not yet, then the server side is listening on the 
remote port which will prevent your new client from estalishing its own remote 
listen. I use "ExitOnForwardFailure yes", which will cause my cleint to abort 
if that happens, and retry. Sometimes it is necessary to go to the remote end 
and kill the old server side sshd (which should self clean up if the remote 
side uses ClientAliveInterval).

Cheers,
Cameron Simpson <cs at zip.com.au>