From: Stephen Hemminger Subject: Re: No UDP NFS over bridges in Linux 2.6.16.x? Date: Fri, 14 Apr 2006 13:53:21 -0700 Message-ID: <20060414135321.53e60516@dxpl.pdx.osdl.net> References: <20060414094042.2a36d377@localhost.localdomain> <20060414192656.870.qmail@web52914.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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 1FUVIJ-0005af-44 for nfs@lists.sourceforge.net; Fri, 14 Apr 2006 13:53:31 -0700 Received: from smtp.osdl.org ([65.172.181.4]) by mail.sourceforge.net with esmtps (TLSv1:DES-CBC3-SHA:168) (Exim 4.44) id 1FUVIH-0001sM-Ik for nfs@lists.sourceforge.net; Fri, 14 Apr 2006 13:53:31 -0700 To: Chris Rankin In-Reply-To: <20060414192656.870.qmail@web52914.mail.yahoo.com> 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: On Fri, 14 Apr 2006 20:26:56 +0100 (BST) Chris Rankin wrote: > --- Stephen Hemminger wrote: > > Most likely the problem is that the MTU on the two devices in the bridge is different. > > The bridge will silently drop packets if they are too large for the destination 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 think that the MTU is the > problem. All the ethernet devices (including the bridge) have an MTU of 1500, and according to my > routing table, only the default route has a lower MTU. Both servers are configured 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 What is the mtu of eth0 and eth1 on the bridge? > > > > > ___________________________________________________________ > Switch an email account to Yahoo! Mail, you could win FIFA World Cup tickets. http://uk.mail.yahoo.com > > > > ___________________________________________________________ > Switch an email account to Yahoo! Mail, you could win FIFA World Cup tickets. http://uk.mail.yahoo.com -- Stephen Hemminger OSDL http://developer.osdl.org/~shemminger ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs