BT Full Fibre 900 FTTP AX88U Setup Guide UK

[Rimmel]

Ok - so I have been messing about with the AX88U and BT Full Fibre FTTP (In the UK). I have had lots of help and support from the people on here (Thank you again), BUT I have discovered the AX88U does not play nice with BT PPPoE connections.

I have had intermittent problems from Day 1 with the AX88U, it drops approx every 12 - 24 hours and seems sporadic with speeds (Upload and Download). Messing with MTU and MRU to get a full connection speed etc etc

To rule the Fibre connection out of the equation, I hooked up the BT Smarthub 2 to the wan connection of the AX88U (double nat) and disabled all of the feathures of the BT Smarthub 2. Basically making the BT Smarthub 2 into a Modem (well not quite... but you get the idea).

Well anyway, all my problems vanished literally over night, full speed stable connection, not dropouts, smooth seemless browsing, gaming and streaming AND I still get to use all the features of the AX88U - with no messing with MTU/MRU settings needed.

BT Smarthub 2 settings:
1) Discconect the Internet cable and do a full hard reset on the BT Smarthub 2

1) Find the recessed "Reset" pinhole button on the back of your Hub.
2) Using a paper clip or similar press the button and hold for 20 to 30 seconds. Your Hub lights will go out and your Hub will restart.
3) Wait a few minutes for the Hub lights to settle. The central Power light will go blue and the Broadband light will be off.

2) Log into the BT Smarthub 2 and immediately disable the Wifi, firewall and Smarthub Setup.

3) Change the Routers/Lan IP so it doesnt conflict with the AX88U. I chose 192.168.234.1 (subnet 255.255.255.0)

Change the DHCP range to to start at 192.168.234.3 and end at 192.168.234.10
Now put the IP address 192.168.234.2 in the DMZ - this will basically forward all traffic to IP 192.168.234.2 without restriction

AX88U Settings - Merlin firmware:
1) Setup the Lan, wireless etc settings as you normally would for your home (I use AiMesh for example) - don't use 192.168.234.x for your lan network, I used 192.168.1.x

2) In WAN settings choose STATIC IP ADDRESS.

Under IP Address put in 192.168.234.2 (remember this is the IP in the DMZ of the BT Smarthub 2)
Subnet mask use 255.255.255.0
Default Gateway 192.168.234.1 (This is the IP/Lan Address of the BT Smarthub 2)
Set DNS servers manually - I used 1.1.1.1 and 1.0.0.1 for UK

Obviously saving everything as you go... now connect the Cable from the BT ONT wall socket (Internet) to the WAN socket of the BT Smarthub 2 router, then connect a DECENT network cable from Lan port 1 on the BT Smarthub 2 to the WAN port of the AX88U router - reboot them both and away you go.

DON'T connect any other lan devices into the BT Smarthub 2 router - use the connection on the AX88U.

The BT Smarthub 2 router is now essentially a modem...

PS You can still access the setup page of the BT Smarthub 2 by typing 192.168.234.1 into the address bar of a browser
PPS I would also recommend putting a really strong password in for Admin access to the BT Smarthub 2 as we disabled the Firewall on this.
PPS You can use your own IP lan settings etc, I just chose the above and they worked for me.
PPPS I am sure I have done things wrong and someone will come along to point this out, but for the moment this is working great for me. Any tweaks/advice welcomed.

 

[ColinTaylor]

Subnet mask use 255.255.255.252 <---- important

This does not need to be set to 255.255.255.252. It will work fine, but technically it ought to match the subnet defined on the Smarthub, i.e. 255.255.255.0.

 

[Rimmel]

This does not need to be set to 255.255.255.252. It will work fine, but technically it ought to match the subnet defined on the Smarthub, i.e. 255.255.255.0.

If you put in 255.255.255.0 the AX88U throws it error and says the "ISP's DHCP isnt working correctly" (or something to that effect). Basically it doesn't work.

Might revisit that...

 

[ColinTaylor]

If you put in 255.255.255.0 the AX88U throws it error and says the "ISP's DHCP isnt working correctly" (or something to that effect). Basically it doesn't work.

That should not be possible because that message is referring to the router's WAN DHCP client. You have disabled the DHCP client and are using static settings instead. Therefore the code that generates that message isn't running.

 

[Rimmel]

That should not be possible because that message is referring to the router's WAN DHCP client. You have disabled the DHCP client and are using static settings instead. Therefore the code that generates that message isn't running.

You are indeed correct, I have ammeded the instructions - thanks

 

[ColinTaylor]

Minor typos:

Smarthub 3)

Change the DHCP range to to start at 192168.234.3 and end at 192.168.234.10

Should be 192.168

AX88U 2)

Under IP Address put in 19.168.234.2 (remember this is the IP in the DMZ of the BT Homehub 2)

Should be 192.
Maybe Homehub should be Smarthub?


P.S. I don't see the point of disabling the firewall on the Smarthub (but then I don't own a Smarthub). I would leave it enabled unless there's a valid reason not to. The firewall's purpose is mainly to protect the router itself, not the clients. On the other hand you have enabled the DMZ which essentially bypasses the firewall anyway so it probably doesn't make a difference either way.

 

[micer45]

Iv'e had BT FTTP installed for about a week now and have had no issues with the AX88U.
I'm on the 500Mbps package and just using the stock firmware 3.0.0.4.388_20499 and the only thing I enabled was IPv6

Speeds seem very consistant and hasn't dropped once.

 

[hash70]

You could buy the bt business smart hub 2 and put it in modem mode,thats what I did,bt hub to rt-ax86u connected with cat6 to another rt-ax86u in the bck room,works without issues

 

[dfunked]

You could buy the bt business smart hub 2 and put it in modem mode,thats what I did,bt hub to rt-ax86u connected with cat6 to another rt-ax86u in the bck room,works without issues

Did you have issues with the AX86U? Mine just worked flawlessly as soon as I plugged it in, which is lucky because the BT home hub never actually got delivered for some reason. Tracking shows that it's still in the Gatwick sorting office over a month after it should've been delivered.

Just curious if this is an issue with the AX88U, or multiple models.

 

[Mr Zippy]

Been using the AX88U for 6 months with no issues with ISP Zen which uses BTs network. Speed 900mbps, no custom settings, it just worked when given the PPPoE login details.

 

[Don->]

Did you have issues with the AX86U? Mine just worked flawlessly as soon as I plugged it in, which is lucky because the BT home hub never actually got delivered for some reason. Tracking shows that it's still in the Gatwick sorting office over a month after it should've been delivered.

Just curious if this is an issue with the AX88U, or multiple models.

My AX88U has worked flawlessly on BT Fibre from Feb this year. I see no disconnects. I have used both ASUS and Merlin varieties of firmware