Tunneling lock/hangs/unidirectional

Corey Smith corsmith at gmail.com
Thu Jan 26 01:30:05 EST 2006

On 1/24/06, Darren Tucker <dtucker at zip.com.au> wrote:
> It looks like the buffer space in your tunnel device is full.  Is the
> SSH stream still running?  If you stop transmitting traffic does it come
> good again?  Are other normal connections to that machine affected?
> You might also like to try picking a fast cipher (arcfour is usually
> fastest of the standard ones) and see if that makes a difference.

Thanks for the response.

I think the buffer space exhaustion is a sympton and not a cause: the
tunnel quits sending so its send buffers get full.  The tunnel between
lab2 -> lab1 fails.  The only thing that would be going through the
tunnel in this test is the ACK stream from the netcat.  Other
connections to lab[12] are not affected during the lock (even other
ssh connections to the same daemon).

AFAIK the tunnel never fixes itself.  If I kill the ssh process that
started the tunnel on lab1 and then restart it the tunnel works
again...  for a while.

I will try using a faster encryption algorithm later today.

-Corey Smith

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