Solved
Hub 5 fails on port 4 when latest firmware upgrade happens - Virgin have their head in the sand (again).
On Feb/26/27 overnight my Hub 5 received an upgrade and the next day port 4 (2.5 gbs) refused to communicate with the switch connected to it. Wireshark indicate (among other things) that all the NIC'...
Long thread about this here. Some users have solved with a managed switch. Hub 5 Firmware Upgrade - Virgin Media Community - 5480079
