On 10/Jun/15 21:56, Robert Drake wrote: > > > When we first were moving to IPv6 in the core network we evaluated > IS-IS because it was what we were using for IPv4 and we would have > preferred to run a single protocol for both. We had problems with > running a mix of routers where some supported IPv6 and others did > not. From what I recall, if any router did not support IPv6 then it > wouldn't connect to a router running v6 and v4. > > It's possible these were bugs and they were worked out later or just a > messed up design in the lab, but we also like the idea of keeping IPv4 > and IPv6 away from each other so if one is broken the other one might > still work.
Someone may have already mentioned this, but you hit that issue because you were probably running ST (Single Topology) IS-IS. IS-IS supports MT (Multi Topology) which allows you to have incongruent IP stacks on a link, i.e., IPv4 on one end + IPv4/IPv6 on another. As the majority of strategies to implement IPv6 will be in this manner, always recommended to run IS-IS in MT mode. Unless you were implementing IS-IS before MT was supported in code. Mark.
