BGP Routing – How to Download Internet Routing Table

GRNET (the Greek Research and Education network) have developed a web application for customers to do this with Flowspec. The web portal has a BGP Flowspec backend which injects flowspec into your network. Highly configurable and in use on the 500-1,000 Gbps pan-European GEANT backbone: https://www.noc.grnet.gr/en/fod

I think BGP is probably your best bet in this situation. The number of tail sites you have quickly exceeds the benefits of most IGPs. BGP would allow you to achieve all of your desired implementation requirements, such as limiting tail site knowledge to the primary/backup DC, standards based protocol, ability to efficiently handle over 5,000 different routes, etc.

OSPF is still an option; I just don’t think it’s the best option. You could always setup each leg of your network as a Totally Stubby Area so inter-area routes aren’t propagated down to the each site. Then you could have separate routing instances at each site to handle their networks independently of your head end.

Each SPF recalculation is going to cost you a pretty penny on resources. How volatile these connections are will affect that, this could be often depending on how aggressive your timing is.

Whatever your decision, BGP was designed to scale. And when anyone says they are looking for a way to scale to 7,000+ networks¹, BGP is a no-brainer.

¹ _{Forecasting based on growth to 1,900 sites x 4 networks at each site.}