From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 8 Jan 2010 22:13:22 -0800 From: Stephen Hemminger Message-ID: <20100108221322.3aaa4fc3@nehalam> In-Reply-To: <4B4674DC.3090602@iders.ca> References: <4B4674DC.3090602@iders.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Bridge] STP on Linux 2.6.30.9 List-Id: Linux Ethernet Bridging List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andrew Cc: bridge@lists.linux-foundation.org On Thu, 07 Jan 2010 17:57:16 -0600 Andrew wrote: > Hey guys, > > I'm working with a bridge I set up on Linux 2.6.30.9. I have two boards > connected and created a redundant connection between them. Basic set up is: > > brctl addbr br0 > brctl addif br0 vlan1 > brctl addif br0 vlan2 > brctl stp br0 on > > Then I bring up the interfaces. Everything seems to be fine. Root > bridge is negotiated properly and leaves both interfaces in forwarding > mode. The other bridge leaves one port in forwarding and puts the other > in blocking mode. However after several seconds a message is printed on > my terminal saying that vlan2 lost it's neighbor and goes through the > listening, learning and then forwarding states. It then quickly flips > back to blocking mode. Is this normal behavior for STP on Linux > 2.6.30.9? Or do I have something else going on here? > > net/bridge/br_stp.c:36 br0: port 2(vlan2) entering blocking state > br0: neighbor 8000.3a:1f:34:08:54:56 lost on port 2(vlan2) > net/bridge/br_stp.c:36 br0: port 2(vlan2) entering listening state > net/bridge/br_stp.c:36 br0: port 2(vlan2) entering learning state > br0: topology change detected, sending tcn bpdu > net/bridge/br_stp.c:36 br0: port 2(vlan2) entering forwarding state > br0: topology change detected, sending tcn bpdu > net/bridge/br_stp.c:36 br0: port 2(vlan2) entering blocking state > > If there's any further information you need, let me know. Bridging two vlan's with STP can be problematic because many switches implement STP on a physical interface (see vlan Spanning Tree). Also, make sure that STP packets aren't being blocked by some firewall rule.