I'd agree with those comments, Les.
I monitor a remote connection using a HG612 that started off with the default IP address of 192.168.1.1, with The PC's NIC set at 192.168.1.100
I changed the HG612's IP Address to 10.0.0.9.
I obviously couldn't then access it via the monitoring PC.
Changing the PC's NIC address to 10.0.0.160 then restored access, but the browser (I.E.) had to be exited & restarted.
The router still uses 192.168.1.254, so for remote access for monitoring purposes, the PC connects wirelessly to the router using an automatically allocated IP Address & the monitoring PC is directly connected to the HG612 using the HG612's LAN2 port.
The remote user still has normal internet access via the router, but cannot access the HG612's stats etc. as his PC is using an IP Address in the 192.168.1.xxx range.