Symptom:
Intermittent connectivity loss between hosts at different OTV sites.  Pinging from one host to the other more than 8 times restores connectivity for about 8-10 minutes.  Packet captures show ARP request broadcasts from a host at one site not being received by the host at the other site for about 7-8s, and then suddenly starting to work.

This problem has a tendency to get worse over time, with more and more hosts being affected over the course of a week or two until connectivity between sites is essentially gone.

Additionally ARP requests both arriving from an Overlay interface or from the inside interface could be lost.

Conditions:
ASR1K running 15.4 or 15.3 code, possibly earlier code, with OTV configured.