Hello Christian
We don’t currently have any lessons on ISIS for IPv6, however, you can visit the following Member Ideas page to make any suggestions for future lesson topics. You may find that others have made similar suggestions to yours and you can add your voice to theirs.
In the meantime, you can visit the following Cisco documentation to get more insight into IS-IS for IPv6.
IS-IS’s support for multi-topology essentially allows the protocol to operate using both IPv4 and IPv6 simultaneously. It removes some restrictions that did not allow this using conventional IS-IS. This Cisco documentation describes it clearly in this way:
IS-IS multitopology support for IPv6 allows IS-IS to maintain a set of independent topologies within a single area or domain. This mode removes the restriction that all interfaces on which IS-IS is configured must support the identical set of network address families. It also removes the restriction that all routers in the IS-IS area (for Level 1 routing) or domain (for Level 2 routing) must support the identical set of network layer address families. Because multiple SPFs are performed, one for each configured topology, it is sufficient that connectivity exists among a subset of the routers in the area or domain for a given network address family to be routable.
For more information, take a look at the link to the documentation, and if you have any further questions, please feel free to ask!
I hope this has been helpful!
Laz