RSVP-TE - BGP-Triggered Automatic Mesh

You can configure RSVP automatic mesh to automatically signal LSPs. When you enable RSVP automatic mesh, RSVP LSPs are automatically created toward the BGP protocol next hop, which cannot be resolved in the inet.3 routing table, eliminating the need to reconfigure all of the provider edge (PE) routers manually, if a new PE router is added. For automatic LSP creation to function properly, you must configure BGP to exchange routes between all of the participating PE routers, because automatic LSP establishment is based on the initial resolution failure of the BGP protocol next hop. If two BGP peers do not exchange routes, an automatic LSP will not be established between them. After automatic LSP is established, the local router's inet.3 routing table will now include a labeled route to the BGP protocol next hop, preventing any further resolution failures toward this BGP protocol next hop.