From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ken Moffat Subject: Re: Lost network connectivity in 4.0.x Date: Thu, 28 May 2015 17:11:19 +0100 Message-ID: <20150528161119.GA31622@milliways> References: <20150524024352.GA15747@milliways> <20150524032938.GA16664@milliways> <20150528144149.GA29350@milliways> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: LKML , Linux Kernel Network Developers To: Cong Wang Return-path: Received: from know-smtprelay-omc-7.server.virginmedia.net ([80.0.253.71]:60652 "EHLO know-smtprelay-omc-7.server.virginmedia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754010AbbE1QLV (ORCPT ); Thu, 28 May 2015 12:11:21 -0400 Content-Disposition: inline In-Reply-To: <20150528144149.GA29350@milliways> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, May 28, 2015 at 03:41:49PM +0100, Ken Moffat wrote: > On Wed, May 27, 2015 at 10:53:00PM -0700, Cong Wang wrote: > > (Please always Cc netdev for networking bugs.) > >=20 Sorry, didn't spot that. But anyway >=20 > > For example: > >=20 > > 1) What is your network setup? iptables? routes? etc. > >=20 > I'm using iptables. Ah, yes - it started dropping packets around > the time I last had a problem: >=20 > May 27 00:48:26 ac4tv dhclient: DHCPREQUEST on eth0 to 192.168.7.254 > port 67 > May 27 00:48:27 ac4tv dhclient: DHCPACK from 192.168.7.254 > May 27 00:48:27 ac4tv dhclient: bound to 192.168.7.152 -- renewal in > 1787 seconds. >=20 > That address came from my router, and I had been getting the same > address for an hour, tbut then the dropped packet messages start > appearing - they are for a different address, one that would have > been offered by my server: >=20 Now that I've had time to think about this and look a bit more deeply, I can see that at one point I got a lease from my server, but then after a random length of time the client tried to renew and got a lease from the router. Some time after that, it failed because iptables rejected the nfs packets because they were "not for me". So, not a kernel problem, and the reason I'm (now) seeing this on 4.0+ kernels is that I have not recently booted a system with an old (3.19 or earlier) kernel and kept it running for a long time. Thanks again, sorry to waste everybody's bandwidth. =C4=B8en --=20 Nanny Ogg usually went to bed early. After all, she was an old lady. Sometimes she went to bed as early as 6 a.m.