IGP Shortcuts and VPNs
You can configure IGP shortcuts for either IS-IS or OSPF. IGP shortcuts allow the IGP to use an LSP as the next hop instead of the IGP route. IGP shortcuts can also be enabled for VPNs by also specifying the bgp-igp-both-ribs or mpls-forwarding options for the traffic-engineering statement at the [edit protocols mpls] hierarchy level. VPNs are dependant on routes stored in the inet.3 routing table. The bgp-igp option for the traffic-engineering statement moves all routes from the inet.3 routing table to the inet.0 routing table and is therefore incompatible with VPNs.