I would not recommend that you use the Smart Hub as an Ethernet switch, as you will lose all traffic if the hub restarts, which it can do quite often. It also going to put a strain on the home hub hardware, and could affect the download speed.
Use a separate Gigabit Ethernet switch, and connect it to a single port on the hub, then if the hub has a issue, you still have interconnectivity.
Communityhelp (Private website) Lots of additional information and help.
You will need to be connected to your home BT Broadband connection to view it, or any links to it that I post on this forum.