A few weeks ago I was working on a customer’s network when I found an OSPF problem. For some reason, an ASA wouldn’t peer with a Nexus switch. To make it a bit weirder, the problem only happened on the default VRF, and only with OSPFv3. On the Nexus side, I could see the ASA neighbour, but it was stuck in INIT. On the ASA side, I couldn’t see the neighbour at all.
You see, I had spent the last few weeks working on a new network design. I had the hardware picked out. The topology was looking good. I even had my cable maps drawn up. Everything was going well.