Is the Nighthawk RAX80 compatible with Australian FTTC NBN?

I believe the information I gave regarding the NBN NCD providing an ethernet connection is correct based on reading I had been doing accross multiple forums. As I said, it takes the VDSL signal from the FTTC splitter in the pit out the front of my house and effectively acts as a modem but it is not directly accessible by the user as it has no built-in PPPoE authentication ability so you cant just plug directly into it as far as I know. So yes, in fact all I needed was a router but I was seeking guidance on how to set it up to authenticate PPPoE with my ISP.

I am writing here for any future readers to tell you YES! It is compatible! All the other info I could find was for lower tier Netgear routers and the settings you need to alter are in different directories for the Nighthawk AX8.

Interestingly, you do NOT need a password to satisfy your login credentials. On the internet setup page on the router home IP address just put in your username without the "@tpg.com.au" suffix. Set the ISP drop down menu to "PPPoE", leave password blank, leave service name blank, connection mode should be 'Always on', Get IP dynamically from ISP and I use 1.1.1.1 as my primary DNS and 8.8.8.8 as my secondary, though this can also be left as get automatically from ISP if you want.

All of that is straightforward, but heres the rub. Alone, it is not enough. You also need to alter the VLAN setting and there is a little trick to that. In the AX firmware you need to select the 'Advanced' tab at the top left of the page. Then select 'Advanced Setup' from the menu on the left hand side and finally select 'VLAN/Bridge Settings'. I dont know enough to say exactly WHY this set-up works, all I can say is that it does. The VLAN ID of 2 is specifically for TPG and I believe other ISP's use other VLAN ID's. As you can see, I have Port4 on its own group and all others on a different VLAN group. The reason for this is, any port that is associated with the group that has a VLAN ID of 2 and priority of Zero becomes inaccessible after you set this up. I was getting very frustrated because once I was swapping all my ports onto this VLAN Tag the internet light on my router was going from amber to white but it became impossible to access my router or internet via any IP address or even routerlogin.net. However, if I left my active ports on a secondary VLAN Tag with a priority of 2, BINGO, my AX8 was now working with no TP-LINK modem, my ping has dropped, my wifi speeds increased from about 37 Mbps to 47 Mbps on back-to-back runs between the budget router included from TPG to my AX8 Netgear router. Also wifi range was SIGNIFICANTLY increased and of course the addition of WIFI 6 which my next phone will almost certainly have. 

I hope this info can help someone else. I probably lost a few years of my life trying every setting I could and resetting the router a million times but it was worth it in the end.