[j-nsp] VPLS Multihoming

[Chris Kawchuk]

On 2012-11-28, at 9:36 AM, Luca Salvatore <Luca at ninefold.com> wrote:

> So - my understanding is that VPLS multihoming is used to prevent layer 2 loops.  How is this accomplished?
> Is it because the backup PE device does not forward any traffic (except for LDP stuff) and hence no loop is formed since backup PE is in a sort of 'blocking' state?

The backup PE signals (to the rest of the network) that it isnt the "designated" PE for that particular site-identifier endpoint (due to the priority setting) via BGP. All the other PEs in the network simply don't forward traffic to it, nor does that 'backup' PE forward any CE traffic into the network. Ergo, no L2 loop.

"show vpls connections" should reflect this state of affairs.

- CK.