[Sephiroth]

The Hub 3 is a well behaved device in my experience. The usual reason for frequent self resets is what is known as a T4 Timeout, when the VM side has made 16 unsuccessful attempts to get a response to its keep-alive signal.

Evidence for this would be found in the Network Log and in the power stats; if the upstream power is very high (in the 50 range) then we can advise you from there. If the downstream power is in deep negative territory, then ditto.

First thing always to check is that the coaxial cable is firmly screwed in both ends.