M-ISIS: Multi Topology (MT) Routing in IS-IS
This draft describes an optional mechanism within ISIS used today by many ISPs for IGP routing within their clouds. This draft describes how to run within a single ISIS domain a set of independent IP topologies that we call Multi-Topologies (MTs). This MT extension can be used for variety of purposes such as an in-band management network ``on top'' of the original IGP topology, maintain separate IGP routing domains for isolated multicast or IPv6 islands within the backbone, or force a subset of an address space to follow a different topology.