18 days ago I was (finally!) connected to HFC but yesterday the NBN Modem's (Arris CM200) upstream light started flashing and the NBN HFC connection went down. I spoke with three people at TPG yesterday and was told that I was still pending installation at the NBN end (despite having been connected for 17 days!), apparently someone didn't update my install status (NBN?). Options were to wait 24-48 hours for NBN to get back to TPG - TPG couldn't advise if there was an outage on my NBN HFC connection as it was pending installation status in TPG's system - or use the ADSL line which is still connected. Tricky as I've flashed my ASUS DSL-AC68U to an ASUS RT-AC68U and redeployed it as an AiMesh node slaved to my new ASUS RT-AX88U (an awesome piece of kit!) but I do still have the TP-Link Archer VR1600v ADSL modem that came as part of my HFC installation. So, why not connect the Archer as a bridge then connect that to my AX88U?
This wasn't that straight forward though and after several hours last night, I called it but later perusing forums I found a message that led to a breakthrough this morning: using the Archer as a bridge requires that VLAN 2 tagging needs to be set only on the Archer and not on the ASUS (and definitely not both as my HFC working connection was).
Here's my working set up for using the ADSL modem in the Archer and acting as a network bridge to my AX88U:
ADSL line <-> Archer <-> Archer LAN1 port <-> AX88U WAN port
Here's what I did to get this working: