Fast Reroute

Requires traffic engineering extensions on OSPF.

Every hop creates one protection tunnel , when facility backup is implemented multiple LSP can be backed up by a single LSP.

When a failure occurs the router closest to the failure provides protection.

There are two methods of FRR protection:-

One-to-One Backup

LSP signaled that is dedicated to protect that LSP-Path. The one-to-one

backup that is signaled is called the

— Each LSP-Path desiring one-to-one backup has a protectiondetour LSP.

• Facility Backup

all LSP-Paths traversing a common facility path. Any LSP-Paths desiring FRR

protection share the common protection tunnel when their paths intersect.

This is a many-to-one protection relationship. The facility backup protection

signaled is called the

— Facility backup creates a common bypass tunnel to protectbypass tunnel.