From: Jay Vosburgh <fubar@us.ibm.com>
To: "Matthew O'Connor" <liquidhorse@gmail.com>
Cc: netdev@vger.kernel.org
Subject: Re: balance-alb and arp-reply stomping
Date: Tue, 08 Jan 2013 09:14:39 -0800 [thread overview]
Message-ID: <31979.1357665279@death.nxdomain> (raw)
In-Reply-To: <CAK8PzV=GN0+txo=ixnKGGUXEeJMfd8=Ce=bSReg_oJXScbs79g@mail.gmail.com>
Matthew O'Connor <liquidhorse@gmail.com> wrote:
>Hi! I've encountered what appears to be a known "issue" with
>balance-alb, whereby when a bond configured thus is put into a bridge
>with virtual ethernet adapters, on reply to arp requests the bond
>appears to "stomp" the MAC of the outgoing replies with one of its own
>adapters' MACs. The consequence seems to be intermittent
>connectivity, easily witnessed by ping-loss early in a virtual
>adapter's life. Checking the ARP cache on another machine shows that
>the virtual adapter's MAC has been replaced with one of the bond
>slaves'. Other bonding modes do not exhibit this behavior.
>
>I was wondering if this is something that had been brought up before
>for fixing, and whether or not you would accept a patch if an
>appropriate fix was implemented? My naive understanding would suggest
>checking the outgoing reply against a table of known slaves, and if
>the MAC did not exist there then map it to a slave and transmit the
>reply unmodified.
This should be fixed in current kernels (to have balanace-alb
mode not modify ARPs that do not originate locally); I see the patch in
the 3.8-rc2 source, but not in the linux-3.7.1 source.
You could apply the patch to an older kernel, it's pretty
simple. The patch itself can be found here:
http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=patch;h=567b871e503316b0927e54a3d7c86d50b722d955
-J
---
-Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com
prev parent reply other threads:[~2013-01-08 17:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-08 16:22 balance-alb and arp-reply stomping Matthew O'Connor
2013-01-08 17:14 ` Jay Vosburgh [this message]
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