All routers bow to your new overlord, ISIS.
Well, since a certain vendor has not tried hard enough to ensure that its newfangled router software plays nice with its older brothers (“stuck in active!”) I decided that it’s time to migrate all the legacy network that was still using eigrp to isis.
Why isis and not ospf you might ask ? Among others because I decided that running two different instances (ospf2 and ospf3) of an IGP to cater both IPv4 and IPv6 is not worth the hassle.
Oh and to keep on the ranting side, of course that the new and the old software has different defaults for isis when it comes to IPv6 (I must admit that the new one is saner thou). Fun.