From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: IP forwarding regression since 3.0-rc6 Date: Fri, 29 Jul 2011 09:33:29 +0200 Message-ID: <1311924809.7845.29.camel@edumazet-laptop> References: <20110725T141145.GA.2ae38.stse@fsing.rootsland.net> <201107281546.33227.maciej.rutecki@gmail.com> <20110729T091342.GA.06bf4.stse@fsing.rootsland.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Maciej Rutecki , linux-kernel@vger.kernel.org, netdev To: Stephan Seitz Return-path: In-Reply-To: <20110729T091342.GA.06bf4.stse@fsing.rootsland.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Le vendredi 29 juillet 2011 =C3=A0 09:15 +0200, Stephan Seitz a =C3=A9c= rit : > On Thu, Jul 28, 2011 at 03:46:33PM +0200, Maciej Rutecki wrote: > >I created a Bugzilla entry at > >https://bugzilla.kernel.org/show_bug.cgi?id=3D40282 > >for your bug report, please add your address to the CC list in there= , thanks! >=20 > Thank you for creating a bug report for me. I have added my address t= o=20 > the CC list. >=20 CC netdev I suspect your configuration is too complex, and maybe the only way to track the bug is to perform a git bisection. Your initial message was : Since 3.0-rc6 I see that my Linux router is losing packets. I can see=20 them tracing the internal interface, but I don=E2=80=99t see them on th= e external=20 interface. I can reproduce the problem while using tin with=20 news.individual.de. At the startup when tin checks every newsgroup from= =20 the server, many packets are suddenly not routed anymore but are droppe= d,=20 so tin hangs until it quits with a NNTP error. All kernels until 3.0-rc5 are working. Hardware: - 2x Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit=20 Ethernet controller Sofware: - Debian Testing, 64bit, with Xen 4.1.0 System: Dom0 (Debian Testing, 64bit) is my working system. The two NICs have ea= ch=20 their own bridge interface. One bridge interface (A) has an internal IP= =20 address (IPv4 and IPv6) of my internal network. The other bridge (B)=20 doesn=E2=80=99t have a IP address in Dom0. The DomU is connected to the= two=20 bridges. DomU (Debian Testing, 64bit) is my iptables firewall system with Bind,=20 Squid, and other services. The interface connected to bridge A has an=20 internal IP addresses (gateway for my internal network). The interface=20 connected to bridge B is used for PPPoE (the NIC is directly connected = to=20 my DSL modem). Kernels: Dom0 has had all kernel versions from 3.0-rcX and is running 3.0 at the= =20 moment. DomU has had the same kernel versions but is running 3.0-rc5 at the=20 moment because of the network problems in newer kernels. Long problem description: From Dom0 I use tin to read different newsserver. One of them is=20 news.individual.de. The first time after DomU switched kernel to -rc6=20 I started tin (connecting to the mentioned news server) and tin hung=20 while reading groups from the newsrc and stopped with a NNTP connection= =20 error. Since the problem didn=E2=80=99t vanish, I wrote a mail to the support = team of=20 the news server. They told me that I was the only one with a connection= =20 problem and asked me to try the connection from another client. I tried= =20 it from my vServer, and it worked. So the problem had to be in my setup= =2E I traced in Dom0 (bridge A), DomU (bridge A) und DomU (ppp0) and notice= d=20 that all packets generated in Dom0 were visible in DomU bridge A. But n= ot=20 all of the packets were visisble at the ppp0 interface. So my DomU was=20 dropping packets and the connection between tin in Dom0 and the news=20 server failed. So I tried older kernels and noticed that 3.0-rc5 in DomU was working,=20 but rc6 and newer were not. The kernel configuration was the same for a= ll=20 3.0 kernels. Since I don=E2=80=99t know which maintainer I should contact with my pr= oblem,=20 I=E2=80=99ll write directly to lkml. Thanks for your help. Shade and sweet water! Stephan