From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: 2.6.31 ARP related problems with multiple macvlan NICs Date: Tue, 01 Sep 2009 06:20:20 -0700 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, Eric Dumazet To: Or Gerlitz Return-path: Received: from out02.mta.xmission.com ([166.70.13.232]:48413 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754622AbZIANUY (ORCPT ); Tue, 1 Sep 2009 09:20:24 -0400 In-Reply-To: (Or Gerlitz's message of "Tue\, 1 Sep 2009 14\:30\:28 +0300 \(IDT\)") Sender: netdev-owner@vger.kernel.org List-ID: Or Gerlitz writes: > Using multiple (e.g 2) macvlan devices set over the same uplink NIC > and 2.6.31-rc7 I can get only one of the macvlan devices to respond on > arp request where the same scheme works fine on 2.6.29.1 and 2.6.30. > > The only devices for which the system responds on ARP request is the > first match in the routing table, e.g mv0 below. Next are the commands > I am using to set the environment that reproduces the problem. > > Looking on net/ipv4/arp.c I do someting that may be related which > was commited for 2.6.30 and reverted for -stable and .31 so the > fact that this test actually works with 2.6.29.1/2.6.30 makes me > think that the problem I see is not directly connected to the "ipv4: arp > announce, arp_proxy and windows ip conflict verification" commit/revert. > > The problem is also not directly related to macvlan, I think, e.g > I have the same issue when having multiple veth pairs connected > to a bridge, only ping to/through the first routing hit works. I just tested. If the two macvlans are in separate network namespaces all is well, so definitely not macvlan. As you have observed there are no real changes to arp.c Interesting I can reproduce this to machines on the same network segment but not to machines on different network segments. Weird. Eric