White Paper Abstract:
Route resolution is the mechanism used in Juniper networks® Junos® operating system to determine the action that should be taken when a route has a next hop that is an IP address. The next hop must go through its own route lookup, and in this sense, how the original route forwards traffic is determined or “resolved.” While there are specific default behaviors for route resolution, it is also possible to change these behaviors by using route resolution configuration commands. Having the ability to change the behavior of route resolution is a very powerful and compelling way for a provider to designate how traffic flows across the network.
By reading this paper, you will gain knowledge about how route resolution works and how it can be configured using Junos os. several example use cases are explained including key router configurations for each use case. The first case describes how to use route resolution along with Multitopology Routing to direct traffic to use an MPls path versus an IP path. The second case shows how route resolution can be used for l3VPn routes. This is particularly useful for a route reflector not enabled with MPls and where ties must be broken on interior gateway protocol (IGP) metrics. Readers of this paper are expected to have a thorough understanding of routing which includes IGP, BGP, and MPls.