Lincoln, Just to be clear:
>>all 'edge' ports should be running with BPDU guard enabled. 'edge ports' (those facing >>hosts) should NEVER send BPDUs out. BPDU guard is there to detect if they do - and if >>they do, its a sign that they have caused a loop in the network. ports with BPDU guard configured still send out BPDUs, but they will *not *allow incoming BDPUs if you also want to stop sending out BPDUs (not recommended), you configure the port additionally with BPDU filter regards, Geert 2009/12/4 Lincoln Dale <[email protected]> > On 04/12/2009, at 1:29 AM, Howard Jones wrote: > > > I've just run into an odd problem, and was wondering if anyone else > > could clarify this for me. > > > > [c1]---[Sw1]----------[Sw2]---[c2] > > > > c1 and c2 are client devices. Sw1 and Sw2 are 3750Gs with a trunk > > between them. c1 has a trunk to Sw1. One of the vlans in that trunk as > > passed along the sw1-sw2 trunk to c2. > > > > The port facing c1 has bpduguard enabled. Halfway through adding vlans, > > Sw2 complains about inconsistent BPDUs, and the root bridge mac address > > is that of c1. It shuts down the trunk port, which is kind of annoying. > > sounds like C1 did something silly. > > > > Does bpduguard only affect access ports and not trunks? That's the only > > explanation I can see for what is going on. The manual doesn't exactly > > say either way: "At the interface level, you enable BPDU guard on any > > interface by using the spanning-tree bpduguard enable interface > > configuration command without also enabling the Port Fast feature.". Sw1 > > also has '|no spanning-tree vlan 1-4090|' - will that help or hinder, > here? > > disabling spanning-tree? that doesn't sound like a very smart move. > > > > I think the real answer is to stop using switches to ship stuff between > > sites like this, but that is a battle for another day. > > nothing wrong with using L2. > > > i think the issue here may relate to your knowledge of switching - and what > spanning-tree is there for, and what its meant to do. > its there to prevent loops. > > make use of it. > > all 'edge' ports should be running with BPDU guard enabled. 'edge ports' > (those facing hosts) should NEVER send BPDUs out. BPDU guard is there to > detect if they do - and if they do, its a sign that they have caused a loop > in the network. > > > cheers, > > lincoln. > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
