Subject: Re: [RFC PATCH 0/2] Faster/parallel SYN handling to mitigate SYN floods

From: Christoph Paasch <[email-masked]>
Date: Wed, 30 May 2012 10:53:08 +0200

On 05/30/2012 10:44 AM, Jesper Dangaard Brouer wrote:
>> > 
>> > Then the receiver will receive two SYN/ACK's for the same SYN with
>> > different sequence-numbers. As the "SYN cookie SYN-ACK" will arrive
>> > second, it will be discarded and seq-numbers from the first one will be
>> > taken on the client-side.
> I thought that the retransmitted SYN packet, were caused by the SYN-ACK
> didn't reach the client?

Or, if the SYN/ACK got somehow delayed in the network and the
SYN-retransmission timer on the client-side fires before the SYN/ACK
reaches the client.

Christoph

-- 
Christoph Paasch
PhD Student

IP Networking Lab --- http://inl.info.ucl.ac.be
MultiPath TCP in the Linux Kernel --- http://mptcp.info.ucl.ac.be
Université Catholique de Louvain
--