I've been troubleshooting an issue with Nexus 7010 dealing with site adjaceny. I have four 7ks (two at each site). Site1-N7K1 is linked via DWDM to Site2-N7K1 over a layer 3 link (the join interface) and this forms an adjaceny. The same happens with Site1-N7K2 and Site2-N7K2.
However I can't get a full adjacency from the N7Ks in the same site over a layer 2 link, even though the site VLAN is definitely up. This is the output from 'sho otv site':