[openssh] Re: Frequent "Connection reset by peer"

[Darren Tucker]

Nadav Har'El wrote:
> On Tue, Jan 29, 2008, Tuc at T-B-O-H.NET wrote about "Re: [openssh] Re: Frequent "Connection reset by peer"":
>> 	I ran what you said, and the first one ran for about
>> 2 minutes and then :
>>
>> Connection to 10.0.0.6 closed by remote host.
>> Connection to 10.0.0.6 closed.
>>
>> 	And the 2nd time about 20 seconds before the same.
> 
> If I understood correctly, what you ran just opened a connection, but passed
> no data for two minutes. Is it possible that your router simply disconnects
> inactive TCP connections after two minutes, in the pretext of saving memory,
> guard against DOS attacks, or who knows what?

Good point, and that reminds me: another thing to check for, 
particularly if you have links with differing MTUs, is fragmentation 
problems:

http://www.snailbook.com/faq/mtu-mismatch.auto.html

A dead giveaway for this problem is if you see a non-zero and increasing 
number in the SendQ column in the "netstat" output for the SSH 
connection (on either server or client end of the connection).

-- 
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.