topic Re: Maybe map-t problem? in Broadband

Maybe map-t problem?

bdog — Sat, 27 Dec 2025 16:36:57 GMT

I've been using openwrt ever since I got Sky and it worked fine. Gave me a public ipv4 all the time. I had to restart the router yesterday and ever since I'm getting a 100. address which is causing problems. I'm use wireguard for my vpn and as well as server/client.

I believe map-t is being used and it has stayed on since no matter how many reboots. I tried the black hub and that seem to have got a public address, I'm a little confused.

I've spoken to a person on cs but they had no clue whats I'm talking about. Can anyone point me in the right direction?

Re: Maybe map-t problem?

JimM1 — Sat, 27 Dec 2025 16:46:31 GMT

@bdog Why don't you keep using the sky Broadband hub if that is what you have connected?

Re: Maybe map-t problem?

bdog — Sat, 27 Dec 2025 16:54:23 GMT

I never used the sky hub, I connected it to check what ip it's getting.

I have wireguard installed on the own router and it worked up to the point it started giving me a private address. I've read a few posts and it's generally to do with map-t. I'm wondering if anyone technical can guide me on having it disabled or any workarounds.

Re: Maybe map-t problem?

JimM1 — Sat, 27 Dec 2025 16:56:54 GMT

@bdog You just need to work it out with what you have on the connection and the equipment that you are using nothing else to it.

Re: Maybe map-t problem?

Chrisee — Sat, 27 Dec 2025 17:47:32 GMT

@bdog Sky can only apply MAP-T to routers that support for DHCPv6 Option 95 which the white Sky Max hubs do and a few third party routers may also support. There was an issue with Ubquiti routers that stupidly advertised support when in practice it did not work. Ubquiti took 8 years to sort this out but did so in a firmware release last year so if tgst could be your problem update the firmware.

Re: Maybe map-t problem?

bdog — Sat, 27 Dec 2025 18:58:40 GMT

It works fine with the map package installed in openwrt, it created a tunnel for ipv4 traffic to work from ipv6. But I can't seem to get native ipv4 support anymore, it's giving me a non-routable 100.126 address. In turn it broke my wireguard setup.

Re: Maybe map-t problem?

JimM1 — Sat, 27 Dec 2025 19:15:26 GMT

@bdog Are you sure that it is not the Router you are using defaulting to a carrier Grade CGNAT type private address when it cannot be issued a wan IP from the sky server! When you put the sky Router back on you seem to be getting a wan ipv4 correct but you do not say if iPv6 is issued also!

Re: Maybe map-t problem?

-rpnz- — Tue, 30 Dec 2025 08:37:03 GMT

@bdog wrote:
It works fine with the map package installed in openwrt, it created a tunnel for ipv4 traffic to work from ipv6. But I can't seem to get native ipv4 support anymore, it's giving me a non-routable 100.126 address. In turn it broke my wireguard setup.

Is your OpenWRT router the Wireguard end-point? It's possible that particular use-case gets confused with the private IPv4 address. In our testing, regular IPv4 connectivity via MAP-T did work with OpenWRT once the MAP package was installed, but not sure we tested that specific Wireguard use-case.

You'll notice DHCPv4 obtains an IPv4 address from 100.64.0.0/10 if you're also using DHCPv6 with MAP-T, this is because on about 30% of Openreach's network we can't use DHCPv6 for authentication and have to rely on DHCPv4 but don't want to waste additional public IPv4 addresses. Sky Hubs will automatically release the lease and stop the DHCPv4 client once they are setup with MAP-T; you could try manually disabling the DHCPv4 client in OpenWRT as it's not required if you're on CityFibre, or the 70% of Openreach's network which can be authenticated using DHCPv6. If you're in the unlucky 30% that requires DHCPv4 to authenticate, it might be worth a feature request/bug report into OpenWRT for it to close the DHCPv4 client if it gets a DHCPv6 lease with MAP-T or other IPv4aaS.