topic Re: ONT won’t connect to my Deco router in Full Fibre

ONT won’t connect to my Deco router

RobinW1 — Wed, 17 Sep 2025 21:07:36 GMT

Hi, I have Full Fibre and an ONT box. I would like to connect my Deco PX50 router directly to it.
I have tried setting the router to PPPoE and putting in my <username>@plusdsl.net and password, but the router isn’t getting internet. The LAN light on the ONT is lit however. Any tips? Thanks

Re: ONT won’t connect to my Deco router

DerekW — Wed, 17 Sep 2025 21:19:02 GMT

Have you checked to see if the VLAN on the Deco is set to off?

If it is set to on then turn it off and try again

Re: ONT won’t connect to my Deco router

RobinW1 — Thu, 18 Sep 2025 05:54:07 GMT

Thanks for your reply DerekW. There is a setting called “IPTV/VLAN” and it is already disabled. No luck so far.

Re: ONT won’t connect to my Deco router

Terranova667 — Thu, 18 Sep 2025 07:10:54 GMT

Hi, From what I have found online you need to set to a dynamic IP if not using one already, disable VLAN settings and using PPPOE, other than that I don't know why it won't connect, you are using the app to setup? it seems that's also a mandatory requirement.

Re: ONT won’t connect to my Deco router

Baldrick1 — Thu, 18 Sep 2025 07:26:11 GMT

@RobinW1

Do you have a Plusnet Hub 2? Does that give you a connection?

Have you checked that your username and password are correct? You can check it by using it to log in to your account.

Re: ONT won’t connect to my Deco router

MisterW — Thu, 18 Sep 2025 07:38:08 GMT

@Terranova667

you need to set to a dynamic IP if not using one already, disable VLAN settings and using PPPOE

and that's the problem with online AI!

Dynamic IP and PPPoE as internet connection settings are mutually exclusive. Disabling VLAN and using PPPoE is correct.

Re: ONT won’t connect to my Deco router

outcast — Thu, 18 Sep 2025 09:31:55 GMT

@MisterW wrote:

Dynamic IP and PPPoE as internet connection settings are mutually exclusive.

No it's not.

Are you getting confused with DHCP ?

On a Plusnet provided broadband, the WAN interface should default to be a "Dynamic IP" (rather than attempting to configure it as static with an associated IP address). By leaving the WAN as being Dynamic IP, then the WAN interface gets assigned an IP address (from Plusnet's servers) as part of the PPPoE session negotiation.

The alternatives to "PPPoE" which ARE mutually exclusive include "DHCP", "PPP", "PPTP", "L2TP", and "Static IP".

I believe that @Terranova667 's post is concise and factually correct -

@Terranova667 wrote:

... you need to set to a dynamic IP if not using one already, disable VLAN settings and using PPPOE,

other than that I don't know why it won't connect.

Re: ONT won’t connect to my Deco router

RobinW1 — Thu, 18 Sep 2025 09:21:57 GMT

1. This further confuses me because on a Deco you have to choose dynamic IP OR PPPoE OR static IP etc.
2. This is a new house and I was told my internet was ready to use yesterday, but just now Openreach texted me saying the setup is complete, so maybe it wasn’t complete when I was fiddling with it! I will be able to attempt again this evening.

Re: ONT won’t connect to my Deco router

outcast — Thu, 18 Sep 2025 09:45:11 GMT

@RobinW1 wrote:

... on a Deco you have to choose dynamic IP OR PPPoE OR static IP etc.

I wonder then if Deco are using the wrong words "Dynamic IP" to describe what every other manufacturer calls "DHCP",

where DHCP is the protocol used to determine the dynamic address and other parameters, for the ethernet WAN interface.

Regardless, in order to make the connection to the internet, the Deco needs to be configured for PPPoE with the associated username and password.

Do you have a Plusnet Hub-2, that you might temporarily use just to prove that the ONT and setup is working, before struggling with the Deco on an unproven connection ?

Good luck with attempting again this evening !

Re: ONT won’t connect to my Deco router

MisterW — Thu, 18 Sep 2025 09:49:44 GMT

@outcast

Are you getting confused with DHCP ?

No , as you can see from the above posts , many routers refer to DHCP as Dynamic IP.

Re: ONT won’t connect to my Deco router

Dan_the_Van — Thu, 18 Sep 2025 09:54:07 GMT

@RobinW1

The quick setup page should look like this

IPv6 should not be enabled.

If the Internet connection is set to Dynamic IP when connected to a network it will use a local DHCP server for its IP Address

Re: ONT won’t connect to my Deco router

Stoker — Mon, 22 Sep 2025 11:13:10 GMT

I have a similar setup but I use the Hub2 (with WiFi disabled) connected to the primary Deco which is in Access Point mode.