[c-nsp] VPLS, spanning tree and redundancy

[Pshem Kowalczyk]

On 26/03/2008, Mateusz Błaszczyk <blahu77 at gmail.com> wrote:
> > > if I understood you correctly there will be two different "VPLS clouds" between both pairs of CSW/PE links?
>
>
> Can I ask why 2 VPLSes instead of one? Is there any technical reasons ?

The main one is so BPDUs from CSW3 and CSW4 can't reach CSW1 at the
same over the same link - a single VPLS cloud would act like a hub
without spanning tree, forwarding packets in every direction that
effectively would stop the L2 network.

kind regards
Pshem