On (2013-03-08 18:17 +0000), Matt Newsom wrote: > If you run PIC and hide the next hop information between a loopback > which is what will happen in a vpn environment
Typical SP network has next-hop-self in INET BGP, and does not carry edge-links in IGP. You don't want to have lot of prefixes in IGP. > If the remote PE has PIC running he can bounce that traffic back to his > backup path via another PE. PIC merely makes sure that FIB is hierarchical and it guarantees all prefixes sharing next-hop converge at same time. Local-repair can be done with or without PIC, as it just means you have local information how to deliver frame to alternate destination without expectation of convergence. > There will be some percentage of your traffic that will then form a transient > micro loop though because that remote PE will have his primary path through > the failed link due to shortest as path length etc Only if egress PE does IP lookup, which is typically does not do (per-prefix or per-ce, default config in 7600, JunOS, IOS-XR) as egress PE label adjacency entry has egress rewrite information. The faulted edge PE can local-repair and get frame delivered without having to wait for BGP to converge for the customer. Transient loop can occur if both of the edges have faulted. -- ++ytti
