From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [PATCH net] bridge: notify user space after fdb update Date: Thu, 29 May 2014 09:55:39 +0200 Message-ID: <20140529075539.GD2942@minipsycho.orion> References: <1401348436-5187-1-git-send-email-jmaxwell37@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: stephen@networkplumber.org, davem@davemloft.net, makita.toshiaki@lab.ntt.co.jp, vyasevic@redhat.com, bridge@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jpirko@redhat.com, jmaxwell@redhat.com To: Jon Maxwell Return-path: Content-Disposition: inline In-Reply-To: <1401348436-5187-1-git-send-email-jmaxwell37@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Thu, May 29, 2014 at 09:27:16AM CEST, jmaxwell37@gmail.com wrote: >There has been a number incidents recently where customers running KVM have >reported that VM hosts on different Hypervisors are unreachable. Based on >pcap traces we found that the bridge was broadcasting the ARP request out >onto the network. However some NICs have an inbuilt switch which on occasions >were broadcasting the VMs ARP request back through the physical NIC on the >Hypervisor. This resulted in the bridge changing ports and incorrectly learning >that the VMs mac address was external. As a result the ARP reply was directed >back onto the external network and VM never updated it's ARP cache. This patch >will notify the bridge command, after a fdb has been updated to identify such >port toggling. > >Signed-off-by: Jon Maxwell Reviewed-by: Jiri Pirko