From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH -next crap] net: icmp: work around bogus pmtu errors Date: Tue, 14 Jul 2015 15:40:09 -0700 (PDT) Message-ID: <20150714.154009.1071789496366560900.davem@davemloft.net> References: <1436572609-2097-1-git-send-email-fw@strlen.de> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: fw@strlen.de Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:53284 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751976AbbGNWkK (ORCPT ); Tue, 14 Jul 2015 18:40:10 -0400 In-Reply-To: <1436572609-2097-1-git-send-email-fw@strlen.de> Sender: netdev-owner@vger.kernel.org List-ID: From: Florian Westphal Date: Sat, 11 Jul 2015 01:56:49 +0200 > sometimes tcp connections seem to hang. > tcpdump shows broken path mtu reports. This "fix" avoids hang and gives: > > [633.327834] icmp: 192.0.0.2 reports mtu 1474 for packet size 1474 to host 204.236.132.12 > [635.586945] icmp: 192.0.0.2 reports mtu 1474 for packet size 1474 to host 54.219.255.254 > [647.106708] icmp: 192.0.0.2 reports mtu 1474 for packet size 1466 to host 204.236.132.12 > [663.084586] icmp: 192.0.0.2 reports mtu 1474 for packet size 1466 to host 54.219.255.254 > > sigh. > > Signed-off-by: Florian Westphal > --- > Might be caused by DS-LITE. I either need the turd below or iptables TCPMSS > mangling rules to artificially lower received mss. > > I don't mind if this is rejected; I'm mostly wondering if anyone > else came across suprise like this. I think the culprit should be identified and fixed ASAP, the last thing we want is for every system add a hack like this.