Multi-Topology IS-IS for IPv4-mapped IPv6
This memo defines two new Multi Topology Routing Identifiers (MT IDs) to be used by the Intermediate System to Intermediate System (M-ISIS, [RFC5120]) routing protocol within a Multi-Topology (MT) context. These new M-ISIS topologies are meant to convey routing information which is specific to IPv4-mapped IPv6 addresses [I-D.ietf-behave-address-format]. The goal of running separate instances for IPv4-mapped IPv6 routes is to isolate the IPv6 routing table from the IPv4 routing table, and to avoid any overload due to the population of the table by IPv4-mapped IPv6 routes. This isolation is motivated also from an operational perspective to enforce specific routing policies for each topology.