Ciena Corporation
Populating capacity-limited forwarding tables in routers to maintain loop-free routing

Abstract:

A router includes a plurality of ports interconnected to one or more Customer Edge (CE) nodes and one or more Provider Edge (PE) nodes; and memory storing a forwarding table of routes, wherein the routes in the forwarding table are installed automatically based on static or Interior Gateway Protocol (IGP)-learned default routes, connected routes, Border Gateway Protocol (BGP) routes learned from peers, and routes in an Internet routing table, and wherein a number of the routes installed in the forwarding table is less than a number of routes in the Internet routing table. The number of routes in the Internet routing table exceeds a capacity of the memory, and the routes installed in the forwarding table ensure a loop-free topology. The routes installed in the forwarding table can include all of the BGP routes learned from peers plus longer prefix matches from the routes in the Internet routing table.