On my list of devices most of them have an IP4 addressing type of DHCP. A couple have a type of STATIC even though they are in the DHCP range. I can't find any way of configuring this. Is it generated by the device?
They'll be manually configured on the device to show up as static on the HG659. Otherwise you can do dhcp reservation on the modem in the menu
Many thanks - this confirms what I suspected.