From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH RFC 0/5] netfilter: implement netfilter SYN proxy Date: Wed, 07 Aug 2013 11:06:06 -0700 Message-ID: <1375898766.4004.37.camel@edumazet-glaptop> References: <1375897371-18430-1-git-send-email-kaber@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: pablo@netfilter.org, netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, mph@one.com, jesper.brouer@gmail.com, as@one.com To: Patrick McHardy Return-path: In-Reply-To: <1375897371-18430-1-git-send-email-kaber@trash.net> Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, 2013-08-07 at 19:42 +0200, Patrick McHardy wrote: > > The SYNPROXY operates by marking the initial SYN from the client as UNTRACKED > and directing it to the SYNPROXY target. The target responds with a SYN/ACK > containing a cookie and encodes options such as window scaling factor, SACK > perm etc. into the timestamp, if timestamps are used (similar to TCP). The > window size is set to zero. The response is also sent as untracked packet. TCP timestamps are not really used, for various reasons ... Have you taken a look at