Traffic Engineering

Traffic engineering enables more effective use of network resources by providing for the setup of explicitly routed Multiprotocol Label Switching (MPLS) label-switched paths (LSPs) that satisfy resource and administrative constraints. You can use OSPF to exchange link resource and traffic-engineering administrative information between routers. OSPF uses this information to calculate paths in the network that satisfy the administrative constraints. MPLS can then set up LSPs along these paths. See JunosE BGP and MPLS Configuration Guide for a detailed discussion of MPLS.

Configuring OSPF for Traffic Engineering

For OSPF to support traffic engineering, you must issue both of the following commands:

By default, OSPF always uses the MPLS tunnel to reach the MPLS endpoint. Best paths determined by SPF calculations are not considered. You can enable the consideration of best paths by issuing the mpls spf-use-any-best-path command. As a result, OSPF considers metrics for IGP paths and the tunnel metric, and might forward traffic along a best path, through the MPLS tunnel, or both.

You can use the show ip ospf database opaque-area command to display information about traffic engineering opaque LSAs.

For OSPF routes to use established MPLS tunnels as next hops—so that traffic can be mapped to use these tunnels—you must configure the tunnels with the tunnel mpls autoroute announce ospf command. See JunosE BGP and MPLS Configuration Guide, for information about configuring MPLS on a router.

mpls spf-use-any-best-path

mpls traffic-eng area

mpls traffic-eng router-id