This isn't a question more a useful tip I discovered the hard way today.
I received my new SuperHub 3 today and set it up. I immediately had a problem when some devices connected to the Internet and some, e.g. media server, wireless access point connected via Ethernet to router and my iMac, didn't but my iMac, for instance, had no problem when connected wirelessly to the router. As I have a few devices that I'd prefer not to have their IP addresses changed I'd configured them with Static IP addresses. The SuperHub 3 doesn't like devices with static IP addresses. The way to do it is to reserve the IP address in the DHCP section of the SuperHub admin Web interface. As the SuperHub has difficulties identifying devices unless they are connected via DHCP you may have to do this manually using the MAC address.
By the way the reason the devices connected wirelessly had no problems is that I never set static IP addresses for the wireless connections so when I connected wirelessly the IP address was set by DHCP and they connected to the internet.