I had a point to point /30 network connection between a Nexus 3172 and a 4506 that was working fine.  I could ssh to the 3172 using the IP address of the interface on this /30 network.  I changed the address on the Nexus to another unused /30 network and tied it into a different port on the 4506 at the far end with the other host IP in the new /30 network.

Now I cannot ssh to the Nexus across that network even though I can ping it and see it as a CDP neighbor.

Any thoughts.