13.2. IS-IS Extensions for Multi-Topology Routing
At the time of writing of this chapter, support for Multi-Topology IS-IS (MT-ISIS) is in the early stages of adoption. As a result, support differs from vendor to vendor. Cisco Systems, for example, supports MT-ISIS for IPv4 and IPv6 unicast topologies, whereas Juniper Networks supports MT-ISIS for IPv4 and IPv6 unicast and multicast topologies. By the time you read this, both vendors likely will support more diverse topology types.
 Tony Przygienda, Naiming Shen, and Nischal Sheth, “M-ISIS: Multi Topology (MT) Routing in IS-IS,” draft-ietf-wg-multi-topology-07.txt, June 2004.
13.2.1. MT-ISIS Procedures
IS-IS is extended to support multiple topologies by defining a new MT Intermediate Systems ...