IS-IS IPv6 Type-Length-Value (TLV) encoding for IPv6 routing is supported in 7210 SAS. This type of routing is considered native IPv6 routing with IS-IS. It has a limitation that IPv4 and IPv6 topologies must be congruent, otherwise traffic may be blackholed. Service providers should ensure that the IPv4 topology and IPv6 topology are the same. With IS-IS multi-topology, service providers can use different topologies for IPv4 and IPv6.
The implementation is compliant with draft-ietf-isis-wg-multi-topology-xx.txt, M-ISIS: Multi Topology (MT) Routing in IS-IS.
The following MT topologies are supported:
MT ID #0 - equivalent to the standard IS-IS topology
MT ID #2 - reserved for IPv6 routing topology