WAN design (dual WAN providers, MPLS, BGP multi-homing)
Posted on 2012-09-12
The customer is wanting to convert to a new WAN architecture that will provide a dual/redundant carrier architecture.
Specifically, they currently have a single MPLS carrier between all of their locations, each site having two circuits into the carrier cloud (single MPLS VLAN, not dual/separate). As they route via BGP to the carrier, each site has a single BGP ASN. The WAN routers perform re-distribution so they do not currently run iBGP between the two carrier CE routers.
The newly proposed architecture is to have a single circuit from the current carrier and another from a new carrier into each site, with each circuit terminated on individual/separate routers. To ensure session load balancing, bandwidth utilization, cost routing, etc., they're hoping for consulting experience/expertise to provide design input.
Stated options/questions include:
- whether to run iBGP between WAN routers and what impact the AS numbering may have
- the most effective (yet simplest) way to run performance routing code, etc that they need to understand how best to run the new WAN architecture
- cutover/migration plans/advice
So, we're looking for examples from similar designs - dual MPLS clouds with divergent carriers and how to design around problems.
Very broad, I know, but any/all input that can be provided would be appreciated. As always, reference links/docs are appreciated.