From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: Re: [PATCH -next 0/2] net: allow setting ecn via routing table Date: Thu, 30 Oct 2014 23:15:01 +0100 Message-ID: <20141030221501.GA9416@breakpoint.cc> References: <1414276729-17871-1-git-send-email-fw@strlen.de> <20141028.165737.2009356944765978630.davem@davemloft.net> <20141029122307.GA29253@breakpoint.cc> <20141030.155958.156984068627586090.davem@davemloft.net> <20141030205204.GE10069@breakpoint.cc> <1414703260.15352.9.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Florian Westphal , David Miller , netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:39793 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934506AbaJ3WPG (ORCPT ); Thu, 30 Oct 2014 18:15:06 -0400 Content-Disposition: inline In-Reply-To: <1414703260.15352.9.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: Eric Dumazet wrote: > On Thu, 2014-10-30 at 21:52 +0100, Florian Westphal wrote: > > > So, what about changing the default to 1 in net-next? > > > > We could add automatic 'no-ecn' to retransmitted syns to avoid > > ecn blackholes (Daniel Borkmann has a patch for this), and, in case > > ecn=1 causes too much breakage we can always revert (and re-consider ecn > > per route settings as an intermediate step). > > > > What do you think? > > I think this is way too dangerous. > > I played a lot with ECN in the past (and fixed number of bugs in linux) > and discovered many times I had to disable it to be able to surf the > Internet. [..] > Reverting might take a long long time, it wont help people stuck behind > buggy equipment. Do you think a fallback to non-ecn for retransmitted syns would help? If not, do you think having ecn tunable available via route is helpful? Thanks!