netdev - Re: [PATCH net] bridge: notify user space after fdb update

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140530073224.2d0baa37@nehalam.linuxnetplumber.net>
Date:	Fri, 30 May 2014 07:32:24 -0700
From:	Stephen Hemminger <stephen@...workplumber.org>
To:	Jon Maxwell <jmaxwell37@...il.com>
Cc:	davem@...emloft.net, makita.toshiaki@....ntt.co.jp,
	vyasevic@...hat.com, bridge@...ts.linux-foundation.org,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	jpirko@...hat.com, jmaxwell@...hat.com
Subject: Re: [PATCH net] bridge: notify user space after fdb update

On Thu, 29 May 2014 17:27:16 +1000
Jon Maxwell <jmaxwell37@...il.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 <jmaxwell37@...il.com>

Acked-by: Stephen Hemminger <stephen@...workplumber.org>
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html