From mboxrd@z Thu Jan 1 00:00:00 1970 From: YOSHIFUJI Hideaki Subject: Re: [PATCH] ipv6: Limit mtu to 65572 bytes Date: Fri, 11 Apr 2014 12:30:18 +0900 Message-ID: <534761CA.1040508@linux-ipv6.org> References: <5345A2B3.7040602@gmail.com> <1397079665.16584.17.camel@edumazet-glaptop2.roam.corp.google.com> <20140409223546.GH27255@order.stressinduktion.org> <1397090170.16584.21.camel@edumazet-glaptop2.roam.corp.google.com> <20140410235459.GK27255@order.stressinduktion.org> <1397176824.16584.52.camel@edumazet-glaptop2.roam.corp.google.com> <1397180530.16584.69.camel@edumazet-glaptop2.roam.corp.google.com> <534753D4.6070600@linux-ipv6.org> <1397186427.16584.86.camel@edumazet-glaptop2.roam.corp.google.com> <534760FD.9050306@linux-ipv6.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Hannes Frederic Sowa , David Miller , Francois WELLENREITER , netdev@vger.kernel.org, YOSHIFUJI Hideaki To: Eric Dumazet Return-path: Received: from 94.43.138.210.xn.2iij.net ([210.138.43.94]:59539 "EHLO mail.st-paulia.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754654AbaDKDaU (ORCPT ); Thu, 10 Apr 2014 23:30:20 -0400 In-Reply-To: <534760FD.9050306@linux-ipv6.org> Sender: netdev-owner@vger.kernel.org List-ID: Eric, YOSHIFUJI Hideaki wrote: > Eric Dumazet wrote: >> From: Eric Dumazet >> >> Francois reported that setting big mtu on loopback device could prevent >> tcp sessions making progress. >> >> We do not support (yet ?) IPv6 Jumbograms and cook corrupted packets. >> >> We must limit the IPv6 MTU to (65535 + 40) bytes in theory. >> >> Tested: >> >> ifconfig lo mtu 70000 >> netperf -H ::1 >> >> Before patch : Throughput : 0.05 Mbits >> >> After patch : Throughput : 35484 Mbits >> >> Reported-by: Francois WELLENREITER >> Signed-off-by: Eric Dumazet > Acked-by: YOSHIFUJI Hideaki Oops, you need to change the subject as well. Otherwise, I am okay. Thanks a lot. --yoshfuji