[c-nsp] Switch mac address appearing in a VLAN going through it

[Gert Doering]

Hi,

On Wed, Dec 14, 2005 at 01:36:10PM +0000, Kristofer Sigurdsson wrote:
> > > What you see is spanning tree packets - that are sourced from the
> > > neighbouring switch (in your case: the 3550).
> 
> Shouldn't "spanning-tree portfast" disable spanning-tree on the
> interface?  

Actually, portfast will not turn off STP, it will just modify it (telling 
rapid-stp that this is an edge-port, and turn off the "listening/learning"
phases of normal STP).  If you build a loop via two portfast-enabled ports, 
the switch will still shut down the port, but only after a few seconds - 
in the mean time, you'll have a loop.

> Also, it has bpdu filters *and* spanning-tree is disabled
> on the VLAN.

Now *that* should really do away with STP packets.  But maybe you are 
instead really seeing VTP or L2 loopbacks...

gert
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