twitch,
If you have a
FTTC service, implying a
VDSL2 metallic path between the cabinet and your
NTE5/A, then you do not need to change any of the
HG612's configuration to establish a connection to just one computer.
Perhaps you should try that first, to gain sufficient confidence? Just perform a long-reset of the
HG612 (at least 10 seconds) and it will be back to the original
Openreach configuration (but will still be unlocked). Now connect your test system to the LAN1 port and configure the system to establish a
PPPoE connection, using the login credentials that are stored in (and supplied by) the router. As you mention "
I have no need for the homehub", I'll take that as confirmation that you are subscribed to
BT Infinity. In that case, the login is "bthomehub@btbroadband.com" and the password is "XXXXXXXX".
I have done exactly as the above, when I took my laptop to my neighbour's home. He has a
BT Infinity service . . . I just disconnected the Ethernet cable that linked the
HG612 to the
HH3.0A and plugged it directly into my laptop computer. A quick setup of a
PPPoE service on my computer and access was obtained.