From: Chris Rankin Subject: Re: No UDP NFS over bridges in Linux 2.6.16.x? Date: Fri, 14 Apr 2006 20:26:56 +0100 (BST) Message-ID: <20060414192656.870.qmail@web52914.mail.yahoo.com> References: <20060414094042.2a36d377@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Cc: bridge@osdl.org, nfs@lists.sourceforge.net Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list2.sourceforge.net with esmtp (Exim 4.30) id 1FUTwd-00050M-TU for nfs@lists.sourceforge.net; Fri, 14 Apr 2006 12:27:03 -0700 Received: from web52914.mail.yahoo.com ([206.190.49.24]) by mail.sourceforge.net with smtp (Exim 4.44) id 1FUTwc-0000T4-EV for nfs@lists.sourceforge.net; Fri, 14 Apr 2006 12:27:03 -0700 To: Stephen Hemminger In-Reply-To: <20060414094042.2a36d377@localhost.localdomain> Sender: nfs-admin@lists.sourceforge.net Errors-To: nfs-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Post: List-Help: List-Subscribe: , List-Archive: --- Stephen Hemminger wrote: > Most likely the problem is that the MTU on the two devices in the bridg= e is different. > The bridge will silently drop packets if they are too large for the des= tination port (it's in > the 802.1d standard). TCP has path mtu discovery and is smart enough to= recover. UDP doesn't do > that. Hi, Thanks for the top about the dangers of NFS and UDP. However, I don't thi= nk that the MTU is the problem. All the ethernet devices (including the bridge) have an MTU of 1= 500, and according to my routing table, only the default route has a lower MTU. Both servers are c= onfigured like this: 192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.x 169.254.0.0/16 dev eth0 scope link default via 192.168.0.1 dev eth0 src 192.168.0.x advmss 1452 eth0 Link encap:Ethernet HWaddr nn:nn:nn:nn:nn:nn inet addr:192.168.0.x Bcast:192.168.0.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:6817 errors:0 dropped:0 overruns:0 frame:0 TX packets:4951 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1840267 (1.7 MiB) TX bytes:678873 (662.9 KiB) Base address:0xdcc0 Memory:ff6e0000-ff700000 So all traffic between 192.168.0.x machines should be routed with an MTU = of 1500. Cheers, Chris =09 ___________________________________________________________=20 Switch an email account to Yahoo! Mail, you could win FIFA World Cup tick= ets. http://uk.mail.yahoo.com =09 ___________________________________________________________=20 Switch an email account to Yahoo! Mail, you could win FIFA World Cup tick= ets. http://uk.mail.yahoo.com ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting langua= ge that extends applications into web and mobile media. Attend the live webc= ast and join the prime developer group breaking into this new coding territor= y! http://sel.as-us.falkag.net/sel?cmd=3Dlnk&kid=3D110944&bid=3D241720&dat=3D= 121642 _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs