Carrier supporting Carrier with BGP-LU
In our last post we talked about the less used method of deploying CsC where we ran OSPF and LDP inside the CSC-PE routing-instance.
Note: I can’t help myself apparently so be aware that Carrier of Carriers (CoC) is the same as Carrier supporting Carrier (CsC)
This required some changes to be made to our default LDP export policy as well as how we moved routes between the inet.3 and inet.0 tables. That being said, if you’re a single org it might make good sense to run things that way. I liked how you were able to see all of the remote LDP domain loopbacks in your local inet.3 table which in my mind made it easier to imagine the LSP paths.
That being said, it is clearly not the preferred deployment methodology. Most examples you’ll find leverage BGP (BGP-LU specifically) for the CSC-CE to CSC-PE connections as well as within the local label domains. So in this example, we’ll do just that. Larges chunks of the base configuration will be the same as they were in the previous post but for the sake of clarity I’ll post our starting post the starting configurations and diagrams here Continue reading



