In reply to a post by amiga_dude:

First you need to know you own router WAN MAC address. Go to the ISP router and set up fixed IP for your own router ie 19.168.1.100

Then on ISP router find DMZ setting and set that to 192.168.1.100 (What your own router is using). As by magic you should be able to port fowared with out issue.

Unfortunately I am unable to change any of that. The only settings that I can change are under NAT Forwarding. In that section I have Virtual Servers, DMZ and UPnP. Virtual Servers seems to have a lot of fields. Does that help!!?

What I know so far is:
1) You have Hay Broadband, package info no idea. Home/Business? 250/1000? https://heybroadband.co.uk/
2) You router you got from Hay Broadbank is TP Link, model/version no idea.
3) You have router. Make/Model/Version no idea.
4) You want to connect your own router (3) to ISP router (2).

As it Hey Broadband then using F&W FTTP.

Alright goto TP-Link 192.168.10.1. So select DMZ. In DMZ sould be only be one field and in there put in 192.168.10.101.

In reply to a post by jimmybond007:

Thanks for this. Trying to keep up. I'm assuming this will be why port forwarding isn't working? If that was, I woiulnt care to be honest.

Anyway, on my router, the WAN is 192.168.10.101. The gateway of the TP LInk (the bbidge is 192.168.10.1.

When I log in to that, it shows me the public IP adress and also a gateway showing 172.16 etc.

Now, Hey Broadband log in remotely to turn their TP Link to bridge mode. Advanced settings has been locked out. So I have no idea whether they have dome this successfully or not. Wireless signals are turned off (but I can do that).

Under networ4k map it shows one wired client (my router), PPOE, Google DNS and that's it. They then emailed me a username and password and told me to put my asus in to PPOE and use the credentials. So all is good other than this odd WAN IP, port forwrading and also it takes my wireless card about a minute to connect to the internet (but they may be another issue!)

Reading your further posts above, I now don't think you are in a bridged connection state at all.

If you have been given PPPoE login credentials from H!B, then you do not need to use the supplied TP-Link router. Take it out of the equation completely.

For the benefit of testing, connect your PC/laptop directly to the Adtran (presumably) fibre ONT ethernet port, setup a connection using the PPPoE login directly. This will connect your laptop/PC directly to their network and the IP address assigned over that PPoE session will be the WAN address. This will doubtless be a DHCP assigned address, however knowing the address range will tell you if its is CGNAT or not - e.g. if this is of the form 172.16.x.x (as per your note above) then that is most certainly a CGNAT range.

I have FTTP 1Gbps up and down
Their router is TP-LInk Archer XR500V
Mine is Asus AX-86U

I cannot put the ONT directly to my router as it's a fibre connection which my router does not have. (only a WAN port)

Done. Said remote management conflict but it's set. So what has that done please?

When you say ONT do you mean the TP-LInk Archer XR500V as it is a GPON router. Does the incoming fibre connect directly to the TP_Link or is there some other hardware?

ONT to TP link via fibre optical cable. TP Link now in bridge mode (according to HB).. Ethernet cable from LAN 1 of TP link to WAN of Asus AX 86U (as per HB instructions).

TP link says PPoE as does Asus.

Public WAN on TP Link and private LAN on Asus.

Problems

1) cant port forward, use DDNS etc
2) wireless drops (but suspect that's a deep Asus router issue so dontt want to confuse matter or go off thread)

After you posted your update with a make and model, it became apparent that your Archer TP-link device is a GPON router. There is no ONT as such as that function is within the unit.

The management clash would appear to show that the TP-Link is still acting as a router and handing out 192.168.x.x local addresses rather than acting as a bridge.

sorry - didnt mean to mislead. I thought the box on the wall was the ONT which then connected to the TP LInk. How can I best explain to IT support (who dont know much) that it isn't in bridge mode...

Escalate to a higher level of support that understands.

You cannot have PPPoE active on more than one ‘network termination’ device on the same broadband service/connection.

Whatever device undertakes PPPoE client connection is granted the WAN address from the PPPoE server/concentrator back in the H!B network. That may or may not be a CGNAT derived address.

It’s then this device which has a direct internet connection and would be responsible for any routing (or indeed NAT, downstream DHCP etc, etc) on your internal network. Forgive me if I’m telling you how to suck eggs here.