This topic

IPv6 setup on PPPoE

beanybaby212 — Fri, 01 Aug 2025 11:33:34 GMT

I have been on the phone with BT technical team and the guy on the phone didn't know what PPPoE was. So here I am.

I have had EE smart hub connected with a pair of TP-links deco's handling the WiFi for a long time now.

IPv6 has been enabled the whole time and have not had any issues.

I have made the decision to want to remove the smart hub and only use my deco's as the main router to avoid any double NAT'ing and maybe, it might be better? Who knows. I also like the features when the deco's are in router mode so thats nice.

Anyway it became unstable and didn't really work until I disabled IPv6. Now it works perfectly fine in PPPoE mode so it seems my IPv6 settings are likely not correct to me.

So here are the options i have with the deco under IPv6:

connection type: PPPoE

sync IPv4 account = Enabled (username = bthomehub@btbroadband.com | Password =BT)

Get IPv6 address = Auto

Prefix Delegation = Enabled

DNS Address = Auto

Assigned Type = DHCPv6

I have read online I must set prefex delegation size to 56 but I do not see that option nor an option to change MTU size to 1500.

Re: IPv6 setup on PPPoE

licquorice — Fri, 01 Aug 2025 12:30:51 GMT

You would be better asking on a TP Link forum.

BT IPv6 is /56 Prefix Delegation.

As far as I'm aware, the PPPoE settings are only required for IPv4

Re: IPv6 setup on PPPoE

beanybaby212 — Fri, 01 Aug 2025 12:55:07 GMT

I already am trying to communicate with them and awaiting their response.

I must select a IPv6 connection type and the options are PPPoE, Dynamic IP(used when connected to my old Smart hub), 6to4 Tunnel, Bridge.

I understand this isn't a TP link forum but somebody must have used TP link devices in PPPoE mode

Re: IPv6 setup on PPPoE

licquorice — Fri, 01 Aug 2025 12:58:29 GMT

Connection type should be Dynamic IP

Re: IPv6 setup on PPPoE

beanybaby212 — Fri, 01 Aug 2025 13:22:22 GMT

I cannot use Dynamic IP as my deco unit is now my router, I do not have the smart hub connected at all.

IPv4 is connected in PPPoE mode which is needed to connect to my BT broadband, why should IPv6 be different?

Re: IPv6 setup on PPPoE

licquorice — Fri, 01 Aug 2025 13:39:15 GMT

Because you authenticate via PPPoE which then gives you an IPv4 address. An IPv6 address is then allocated via Dynamic addressing.

Re: IPv6 setup on PPPoE

WSH — Fri, 01 Aug 2025 13:47:01 GMT

Have a go at turning the DHCPv6 off. If it's getting an IPv6 address native the usual arrangement would be to let your devices use SLAAC and not DHCP.

(And double NAT's an overrated issue. It's only usually a problem if you host multiplayer games or run your own externally accessible servers).

Re: IPv6 setup on PPPoE

beanybaby212 — Fri, 01 Aug 2025 14:10:30 GMT

I have tried Dynamic IP and it wont retrieve any IP address it just does nothing, with PPPoE it does get an IP address.

According to few sources online BT uses DHCPv6? I have the option of choosing either ND Proxy, SLAAC+Stateless DHCP or SLAAC+RDNSS but I cannot just turn it off.

I understand your point, I have reached this point so far and I know it should work though.

Re: IPv6 setup on PPPoE

licquorice — Fri, 01 Aug 2025 14:24:13 GMT

The DHCPv6 setting is the LAN configuration not the BT side. Set that to SLAAC and the devices should auto configure in line with the /56 Prefix received.

Re: IPv6 setup on PPPoE

beanybaby212 — Fri, 01 Aug 2025 14:51:10 GMT

I have changed to SLAAC but here is something else..

I have the option to 'Sync to IPv4 account' which I have had enabled. When this is like this I receive an IP address that I can read on my deco app. This is when the network is very unstable. If I untick Sync and manually enter the same username and password on the IPv4 side I no longer get an IP address, the internet is then fine but assuming all this does is act like I have disabled it.

This is looking like a TP link issue more and more

Re: IPv6 setup on PPPoE

beanybaby212 — Fri, 01 Aug 2025 15:10:21 GMT

Another thing to add

I have reverted back to smart hub and then deco changed to dynamic IP mode.

I now not only receive an IP address on the IPv6 tab in the deco app but also a Primary DNS address that I didnt before.

Whilst in this setup I have tried https://ipv6test.google.com/ , which tells me I don't even have IPv6.

Re: IPv6 setup on PPPoE

licquorice — Fri, 01 Aug 2025 15:36:09 GMT

https://www.loopsofzen.uk/ is an IPv6 only site. if you can access it, you have IPv6.

Re: IPv6 setup on PPPoE

beanybaby212 — Fri, 01 Aug 2025 15:42:43 GMT

I cant access it. Thats with Smart hub connected up.

So now this may all be down to BT/EE now?

Re: IPv6 setup on PPPoE

beanybaby212 — Fri, 01 Aug 2025 15:45:28 GMT

Apologies, so I have connected my ethernet directly into the smart hub now and I can access it. So I guess this proves BT is working correctly.

I am so unsure what to do next, still awaiting responses from Tp link team.

Re: IPv6 setup on PPPoE

WSH — Fri, 01 Aug 2025 16:04:27 GMT

Sorry, been up the road for a haircut.

Which version of SLAAC are you using? I'd use the RDNSS version then it uses the router advertisement to for the DNS address etc. The DHCP version gets that from DHCP and if that is causing problems...

As Licquorice says, the DHCP you were using is the one that issues addresses to devices in your own network. It is completely separate to the DHCP BT are using to supply the public address.

Re: IPv6 setup on PPPoE

beanybaby212 — Fri, 01 Aug 2025 16:28:35 GMT

Well at the minute with what I have learned now is I don't seem to be able to use IPv6 at all with my deco's connected to the smart hub via Dynamic IP or PPPoE with no smart hub.

Possibly the unstable issue I started with is linked to this.

Erm the assigned type I've used all now except ND proxy and doesn't change anything.

The only way I can connect to IPv6 addresses seems to be when I do not use deco at all.

Re: IPv6 setup on PPPoE

beanybaby212 — Sun, 03 Aug 2025 16:00:27 GMT

I seem to have fixed the problem FYI.

I have read a few other posts and changed the 'Get IP address' to Non-Address and its solved the whole thing.

Finding this info was quite challenging luckily a few others on here have deco's.

Thanks for the help