Stange sshd problem... bug?

[Darren Tucker]

Chris Rapier wrote:
> Darren Tucker wrote:
>> Try (as root):
>> echo 0 >/proc/sys/net/ipv4/tcp_window_scaling
>> 
>> and if that helps then read this for details:
>> http://kerneltrap.org/node/6723

> As a note: if this does work then its important to realize that you 
> haven't fixed the problem you have only identified what the problem is. 
> This really only swaps one set of problems for a much larger set of 
> problems (albeit one of performance rather than connection establishment).

That's true, and if this proves to be the reason then ideally the root 
cause (ie the network device that's not handling window scaling 
correctly) should be fixed.

The catch is that this may be outside of the control of the folks 
affected by it.  In that case you have a choice of "fast and flaky" or 
"slow and reliable", and which is preferable would depend on what you're 
trying to do with it :-)

As another aside: the assertion in that kerneltrap article that there's 
a bug in OpenBSD's pf and it its handling of TCP window scaling appears 
to be incorrect (although it is possible to misconfigure pf to cause 
this problem, see http://www.benzedrine.cx/pf/msg05117.html).

-- 
Darren Tucker (dtucker at zip.com.au)
GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4  37C9 C982 80C7 8FF4 FA69
     Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.