[j-nsp] MX Design

[Clarke Morledge]

Johan,

Regarding your question about whether or not to run MSTP up to a pair of 
MX distribution routers from downstream EX's, I wrestled with this for 
awhile several years ago.  I had a devil of a time trying to get Link 
Aggregation (LAG) to work even between two MX routers reliably without 
introducing other issues in the pre-10.4 days, so I gave up on it.

The idea of Multi-Chassis LAG active/active does sound inviting, but I 
guess I am a bit shy still about LAG in general introducing weirdness and 
bugs.

I really would like to see Juniper embrace IEEE802.1aq Shortest Path 
Bridging or the IETF RBridges, but with the current emphasis on QFabric I 
am not holding my breadth.   At this point, waiting for  BGP MPLS Based 
MAC VPN is a more realistic down-the-road type of thing from Juniper.

In the meantime, we opted to bringing MSTP up into the MX routers and make 
one of MX routers the root and the other a backup root.  We lose use of 
one of the links, but at least it has been very stable over the past few 
years, and I stay away from proprietary solutions.

Clarke Morledge
College of William and Mary
Information Technology - Network Engineering
Jones Hall (Room 18)
Williamsburg VA 23187