TCP RST question

[Michael Tüxen]

On Jul 31, 2009, at 3:57 PM, <Hartmut.Brandt at dlr.de> <Hartmut.Brandt at dlr.de 
 > wrote:

> Hi all,
>
> I'm looking at our TCP stack and found a change that was introduced  
> with
> the syncache. The original BSD code did send an RST segment when the
> connection timed out in SYN-RECEIVED. The TCP would retransmit the
> SYN+ACK several times and then give up and RST the peer.
>
> With syncache, however, our TCP doesn't send the RST anymore. It just
> silently discards local state.
>
> So the question is whether TCP is supposed to RST or not. Looking at
> RFC793 I found nothing useful. It talks about sending RSTs as response
> to incoming segments and it looks like TCP is never supposed to give  
> up
> retransmitting. The state diagram has no line from SYN-RECEIVED to
> CLOSED. Stevens, on the other hand, has this line and it is labeled
> 'send: RST'.
>
> So the questions are:
>
> - is TCP supposed to send an RST when it times out in SYN-RECEIVED?
> - why was this changed (I suppose it is just one of the regressions
> introduced with the syn-cache).
>
> harti
>
> NB: does anybody know a good mailing list where this kind of questions
> can be discussed?
tsvwg at ietf.org
tcpm at ietf.org

Best reagrds
Michael
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