Segment Routing — SR-MPLS and SRv6

Segment Routing Fundamentals

Segment Routing eliminates the need for per-path signaling protocols like LDP and RSVP-TE by encoding the forwarding path as an ordered list of segments in the packet header. Each segment represents a topological or service instruction — a node segment identifies a destination router, an adjacency segment specifies a particular link, and a prefix segment identifies a network prefix. The source router computes the desired path and encodes it as a segment list. Intermediate routers process one segment at a time, forwarding the packet toward the current active segment without maintaining any…