Re: [tcpm] SYN in SYN_RCVD state

Joe Touch <touch@ISI.EDU> Mon, 22 October 2007 22:03 UTC

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Date: Mon, 22 Oct 2007 15:00:44 -0700
From: Joe Touch <touch@ISI.EDU>
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To: Ted Faber <faber@ISI.EDU>
Subject: Re: [tcpm] SYN in SYN_RCVD state
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Ted Faber wrote:
> On Mon, Oct 22, 2007 at 12:37:23PM -0700, Vishal Study wrote:
>> Hi Ted:
>>
>> The server would retransmit SYN+ACK when server times out in SYN-RECEIVED state.
>> I agree and have seen this.
>>
>> But, when the server hasn't timed out in SYN-RECEIVED state and it
>> receives retransmitted SYN from client (due to client's timeout), what
>> is the expected behavior on server side? Is server supposed to send
>> SYN+ACK?
> 
> The spec says no. 

Agreed. FWIW, Ted already said there are two separate events:

1) the arriving retransmitted SYN causes the server to send an ACK

2) a timeout on the server associated with sending the SYN-ACK goes off,
and the server resends the SYN-ACK then

(1) doesn't cause (2); timeout does.

Joe

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