Compact Routing Header (CRH) Helper Option

This document introduces a new IPv6 Destination Option called the CRH Helper. The CRH Helper is used with the Compact Routing Header (CRH) [RFC 9631]. It contains information required to convert a CRH SID to the IPv6 address of a interface on a packet's delivery path. Because the CRH Helper contains this information, it eliminates the need for a CRH-FIB. It also eliminates the need for CRH-FIB support in the control plane. The CRH helper is useful in underlay networks, where all interfaces are numbered from a few /112 or /96 prefixes.