I found a kind of interesting failure mode tonight, and I wanted to throw it out there to see if any others have had this happen. Power-cycling the MoCA adapter did fix it, at least for now, so it's not a big deal, but I'm hoping it won't become a recurring problem.
The problematic MoCA adapter has only one thing connected to it: a UniFi wireless AP. I noticed an issue that while the AP was on the network and appeared healthy, clients of it were having connectivity problems. Some traffic could pass. For example, clients were able to get DHCP leases, pings worked, it seemed like DNS lookups were working. But HTTP definitely did not work. I initially blamed this on an issue with the AP, so I actually replaced the AP, but the problem persisted, and only then did I think to investigate the MoCA adapter. Immediately upon powercycling the MoCA adapter, the problem went away.
I didn't think MoCA operated at a layer that could cause this kind of issue, but maybe it was something with packet size? I'll confess that I don't know much about the actual technical implementation of MoCA...
Anyway has anyone seen this? I have four goCoax MoCA adapters on my network, in operation for probably about 1.5 years, and this is the first issue I've had.