This document describes the use of loop-free alternates to provide
local protection for unicast traffic in pure IP and MPLS/LDP networks
in the event of a single failure, whether link, node, or shared risk
link group (SRLG). The goal of this technology is to reduce the
packet loss that happens while routers converge after a topology
change due to a failure. Rapid failure repair is achieved through
use of precalculated backup next-hops that are loop-free and safe to
use until the distributed network convergence process completes.
This simple approach does not require any support from other routers.
The extent to which this goal can be met by this specification is
dependent on the topology of the network. [STANDARDS-TRACK]