RFC 8667: IS-IS Extensions for Segment Routing

Segment Routing (SR) allows for a flexible definition of end-to-end paths within IGP topologies by encoding paths as sequences of topological sub-paths, called "segments". These segments are advertised by the link-state routing protocols (IS-IS and OSPF). This document describes the IS-IS extensions that need to be introduced for Segment Routing operating on an MPLS data plane.