Routing

why do we need multihoming

Hi Robbie,

In VPLS multihoming you have to prevent the layer 2 loop to occur in your network:

 BGP VPLS :  to prevent loop we put the same RD and same site id ,  only one path will be active (highest site-preference) and the other provide backup path.

 LDP VPLS: we configure the remote PE to choose one active path.

Regards,

Khaled.

LPI, CCNP, JNCIS-SP

Juniper has published a Network Configuration Example (NCE) for VPLS Multihoming.

Next-Generation VPLS for Multicast with Multihoming Using BGP

http://www.juniper.net/techpubs/en_US/junos12.2/information-products/topic-collections/nce/ng-vpls-p2mp-multihoming/ng-vpls-for-multicast-with-multihoming.pdf

The overview has some information on setting the RD and site ID.

http://www.juniper.net/techpubs/en_US/junos12.2/topics/concept/ng-vpls-p2mp-multihoming-overview.html

A new VPLS multihoming example will be published with Junos OS 12.3.

To see all the NCEs go to:

http://www.juniper.net/techpubs/en_US/junos12.2/information-products/pathway-pages/nce/index.html

Hope this helps.

Regards

Roy

NCE Project Manager

why

Hey Robbie,

 If you use the same RD and site-ID, they can't co-exist together. In other words, one will have to be active while the other is backup, hence eliminating the risk of loops.

Cheers,

.......

You can have different RD, just as long as site ID is the same.

Basically the router that is configured as the backup for the site doesn't forward any traffic, so there is no chance of a loop

True, apologies if I was the source of the confusion.

Cheers,