@Dizzwold 

Hi,

A few comments for your information.

Regular TP-Link Wi-Fi routers (i.e routers without built-in DSL modem) do not have the "MER" option. The GX90 is no exception.

The thread you mentioned is specifically about TP-Link routers that have a built-in DSL modem, therefore it is not really relevant for your GX90.

If the NOW modem/router was providing Wi-Fi access, then it is running in router mode (and not bridge mode), which means you don't need to setup any "Sky(MER)_VDLS" stuff on the GX90. Instead select "Dynamic IP" for the GX90's Internet connection and then connect the GX90's Internet (WAN) port to one of the LAN ports of the NOW modem/router.
The only disadvantage in this setup is that you would introduce a so-called "double-NAT" condition, which has been a problem for some users.

Dizzwold wrote

 

 I've been advised that with Shell Broadband you can put their modem/router into Bridge Mode.

 

I've spoken to Shell and they've advised me, if I was to join them and wished to use my own router they would give me the username and pass word to do so.

 

When you talked to them did they confirm to you that they don't use any weird authentication method like "MER"?
Because if they did, then you wouldn't gain anything by switching to them.
However, if they've already confirmed to you that they use standard PPPoE with pure username and password authentication, then you should be fine.

  @woozle 

 Hi Woozle,

 Thank you for your reply, I'm really grateful.

 I did actually find something on the 'double NAT' scenario yesterday, an believe this is the problem I'm experiencing.

 With my GX90 wired from the NOW Broadband router with the WiFi disabled, the |GX90 isn't findiing some devices (home assistant for one on RPi), yet 2 different IP Scanners find it.

 I guess it's time to move on from NOW.

 Thank you again for your time.

Dizzwold.

  @Dizzwold 

Double NAT should only cause problems in some scenarios where something on the external network (i.e. the Internet) needs to have direct access to something on the internal network (i.e the router's LAN). 

Anyway, if you deem that this is what you need, then make sure beforehand that Shell does indeed provide the following:
- a "public IPv4 address" is assigned to your router's Internet connection
- an authentication method that is supported by your GX90 is being used

I can't post links here in this forum, but if you search via Google you should find a Shell page titled "What if I want to use my own router?". There it says if you've subscribed to their "fibre packages", then the connection type is PPPoE, but for their "Fast Broadband" service the connection type is apparently "PPPoA", which I doubt the GX90 supports.