Part II: Inter-domain Routing Policies. traffic. traffic. What is routing policy?. ISP2. ISP1. Connectivity DOES NOT imply reachability!. ISP3. ISP4. Cust1. Cust2. Policy determines how traffic can flow on the Internet. BGP routing process. Apply input policy. Apply output policy.
Part II: Inter-domain Routing Policies
Connectivity DOES NOT imply reachability!
Policy determines how traffic can flow on the Internet
BGP is not shortest path routing!
[1 2 3], [1 2 6 3] are valley-free
[1 4 3], [1 4 5 3] are not valley free