Date: Tue, 07 Mar 2006 14:45:49 +1100 From: Nik Lam <freebsdnik@j2d.lam.net.au> To: Andrew Thompson <thompsa@freebsd.org> Cc: freebsd-net@freebsd.org Subject: Re: if_bridge steals IP address of non-member interface Message-ID: <440D01ED.1050907@j2d.lam.net.au> In-Reply-To: <20060307025410.GA55053@heff.fud.org.nz> References: <440CEBDE.5090602@j2d.lam.net.au> <20060307025410.GA55053@heff.fud.org.nz>
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Andrew Thompson wrote: > On Tue, Mar 07, 2006 at 01:11:42PM +1100, Nik Lam wrote: > >> I'm not sure if what I'm seeing is an artefact of me doing something >> unusual with my design or if there is a bug in if_bridge. >> >> I'm dividing my LAN into two parts using a pair of intel pro 1000 (em) >> interfaces in an if_bridge bridge. I've configured this bridge with STP >> (802.1d) although I don't think this should be the cause of the >> problem. On the same host which is doing the bridging, I've got another >> interface (fxp0) which is configured "normally", i.e. it has an IP >> address on the subnet which the bridge divides. >> >> Generally this setup works fine, however every now and then I find that >> the bridge is answering ARP who-has queries for the IP address assigned >> to fxp0. >> > > Can you try this patch. > > cheers, > Andrew > Hi Andrew, Your patch seems to have done the job. I have two identical (for all intents and purposes) machines, one patched the other not. I did a tcpdump for arp packets on both em0 and fxp0 of each host and initiated some arp who-has queries for the IP addresses attached to the fx0 interface on each host. On the patched machine only the fxp0 interface sent an arp-reply. On the unpatched machine not only did fxp0 reply but the em0 interface sent both it's mac as well as the mac of em1, the other side of the bridge. I've done this five times in a row and consistently got the same result. Thanks, Nik
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