Segment routing

Segment routing, a form of <a href="/facts/Computer_networking/3w5RM99p">computer networking</a>, is a modern variant of <a href="/facts/Source_routing/1Xtpqwby">source routing</a> that is being developed within the <a href="https://datatracker.ietf.org/wg/spring/about/">SPRING</a> and IPv6 working groups of the <a href="/facts/IETF/tIcCsFhX">IETF</a>. In a <a href="/facts/Network_segment/D0gAdNdR">segment</a> routed network, an ingress node may prepend a <a href="/facts/Header_(computing)/DSbn3tM1">header</a> to <a href="/facts/Network_packet/xCYf8SJu">packets</a> that contain a list of segments, which are instructions that are executed on subsequent nodes in the network. These instructions may be forwarding instructions, such as an instruction to forward a packet to a specific destination or interface.
Segment routing works either on top of a <a href="/facts/MPLS/k7cx1PWw">MPLS</a> network or on an <a href="/facts/IPv6/d4dg7kIL">IPv6</a> network.
In an MPLS network, segments are encoded as MPLS <a href="/facts/Label_switching/otkEnUE5">labels</a>. Under IPv6, a new header called a Segment Routing Header (SRH) is used. Segments in a SRH are encoded in a list of IPv6 addresses. The 5f00::/16 prefix has been allocated for this purpose as part of an Internet-Draft.

Segment routing open-in-new

Segment routing