What must a network engineer consider when designing a Cisco MPLS TE solution with OSPF?

For a Cisco MPLS Traffic Engineering (TE) solution to function correctly with OSPF, the OSPF TE extensions (to advertise link-state attributes relevant for TE) and RSVP-TE (to signal and maintain TE tunnels) must be enabled on all routers participating in the MPLS TE domain. This ensures that all routers can properly advertise TE capabilities, build the TE topology, and establish traffic-engineered paths.

OSPF extensions for RSVP-TE are not exclusively or specifically supported only in Area 1; they can be implemented across various OSPF areas, particularly in the backbone and standard areas.

Enabling OSPF extensions and RSVP-TE only on egress routers is insufficient; all intermediate routers that are part of a potential TE tunnel path must also have these capabilities enabled to participate in traffic engineering.

OSPF TE extensions for RSVP-TE primarily utilize OSPF Opaque LSAs (Type 9, 10, and 11) to carry TE-specific link attributes, not Type 6, 7, and 8 LSAs.