This topic

IPv6 Not Enabled

John91 — Mon, 09 Oct 2023 20:21:31 GMT

@RobbieMac I'm also experiencing the issue of not having IPv6 enabled, however mine is to do with the WAN connection on the BT side. Specifically to do with the DNS (Domain Name System) servers only being IPv4, this could involve both the type of connection them being on an IPv4 network and/or only being able to resolve a domain name to an IPv4 address.

However over a period of time I have been experiencing more and more issues, with sites which previously worked but from looking around at other places its become apparent that its because they have gone IPv6 only! I have been having trouble getting BT to enable IPv6 DNS on Super Fibre, as unfortunately where I am currently can't receive FTTP.

I have been trying to get the support team to get it to the right person so they can enable the WAN DNS for IPv4 and IPv6 together. But it has proven very difficult to reach the right individual so they can make the changes, to make matters worse I kept losing the phone connection.

The connection isn't a new one just been around for quite a while, but needs the new IPv6 functions so can get the full internet functionality.

I'm also reaching the point where I need to contact OpenReach in order to get this sorted, is this really necessary? Shouldn't all customers (FTTP and FTTC) be getting the IPv6 Full Stack (IP, DNS and Gateway) so they can access the full internet, and not be left in an ever shrinking pond as there's less and less with IPv4?

Re: IPv6 Not Enabled

licquorice — Mon, 09 Oct 2023 20:32:59 GMT

BT do not have IPv6 DNS servers. IPv4 DNS servers serve both IPv6 and IPv4 addresses.

Re: IPv6 Not Enabled

John91 — Mon, 09 Oct 2023 21:10:35 GMT

Well if they have DNS serving both IPv4 and IPv6 on an IPv4 server, can they please implement a full IPv6 DNS server to roll out. As for one thing the format of IPv4 and IPv6 don't work really well together due their formats being different, and for another matter it puts more load on routers which are trying to handle the requests including more network latency. Both on the ISP's network and on the customer's. Also it prevents the use of IPv6 only across both the ISP's network and their customer's due to it only being on IPv4.

Additionally technological features which are present in IPv6 can't be used really without being full stack, such as the following features:-

Privacy extensions
Mobility
IPsec
Simplified processing by routers
Extension headers
Jumbograms

Given that BT is in the process of rolling out Full Fibre while supporting Super Fibre only having an IPv4 DNS on their network is short sighted. As this will prevent their customers from being able to use the internet to its fullest possible extent.

By going dual stack (2 full networking stacks - IPv4 and IPv6) which is the best possible outcome for BT's customers as they will be able to communicate effectively, and will continue to be able navigate the web through its domain names irrespective of the networking stack.

Re: IPv6 Not Enabled

licquorice — Mon, 09 Oct 2023 21:12:12 GMT

I don't follow your logic. A DNS server is just a glorified telephone directory, why does it have to have an IPv6 address in order to dispense lookups for both IPv4 and IPv6?

If you are that bothered about it, don't use BT's DNS servers.

Re: IPv6 Not Enabled

John91 — Mon, 09 Oct 2023 21:24:26 GMT

It's not so much the DNS but it is important but the situation that both stacks have its DNS on an IPv4 address. When you get the best benefit when the IPv6 traffic is handled by a DNS that's on the IPv6 stack, as it enables the resolution of hostnames by IPv6 addresses which are using one of the Privacy extension options (e.g. EUI64). Also the format is much different (e.g. 192.168.1.100 - IPv4 and fd57:4dd1:2ac5::/48 - IPv6).

@licquorice Also by the way there's not much choice as this change needs to be network wide and are using BT's Smart Hub 2's which don't allow custom DNS settings.

Re: IPv6 Not Enabled

Crimliar — Mon, 09 Oct 2023 21:24:12 GMT

DNS servers do little more than take human-readable addresses and return IP addresses and for those of us with working IPv6 (and our own routers), there is nothing to prevent using independent DNSv6 servers. There is no magic that prevents an IPv4-accessed DNS server from also returning the correct IPv6 addresses to clients. So far as I can tell, the rest of the IPv6 stack is all in place for many of us! With the current state of the web, it would be far easier to live with single-stack IPv4 than with single-stack IPv6, obviously, dual-stack is better still!

Re: IPv6 Not Enabled

licquorice — Mon, 09 Oct 2023 21:22:33 GMT

@John91 wrote:

@licquorice Also by the way there's not much choice as this change needs to be network wide and are using BT's Smart Hub 2's which don't allow custom DNS settings.

Indeed, but there are ways around that.

Re: IPv6 Not Enabled

John91 — Mon, 09 Oct 2023 21:35:38 GMT

@Crimliar Have you tried running a system where it only has IPv6 active? I have and the missing IPv6 stack based DNS has caused no end of trouble.

Cause its likely that eventually there will only be IPv6 so getting this sorted out now with a native IPv6 stack based DNS is best!

Re: IPv6 Not Enabled

licquorice — Mon, 09 Oct 2023 21:44:40 GMT

I have just disabled IPv4 on my device and have no trouble accessing IPv6 only sites, why would I?

Re: IPv6 Not Enabled

Crimliar — Mon, 09 Oct 2023 22:00:23 GMT

Single-stack IPv6 will not be a viable option until all those sites you want to connect to are accessible via IPv6 - many are not. This means any attempt to currently use a pure IPv6-only stack is going to go badly even if you have DNSv6.

And yes, using Hurricane Electric's "tunnelbroker.net" I've run with everything passing through IPv6 - though that setup is not pure as in order to access many sites that themselves haven't implemented IPv6 it then has to bridge back to IPv4. Also in a different set-up, it's possible to have DNSv6 servers handing clients the IPv4 addresses they need!

At the moment and for a while to come, it's transitional, pretending that it's not is only going to spite yourself!

*I have the IPfoo extension in the browser and there are tabs open there that indicate as fully IPv6.

Re: IPv6 Not Enabled

John91 — Tue, 10 Oct 2023 13:46:59 GMT

Even if you don't go single stack. Being native IPv6 right through to the end of the ISP network (WAN) for now will benefit us all.

As for one thing addresses which aren't translating (bridging) very well between IPv4 and IPv6 are adding additional load, due to not being able to simplify processing by routers and also introducing opportunities for black hole connections. For the average user it results in more load on routers at the ISP, which then impacts our own internet connection performance and also access to services which aren't bridged well due to non-native end-to-end ipv6 especially when using the features which are only in IPv6.

The area where the problem is most noticeable is when using application protocols which are embedding Internet-layer addresses, where new address format are able to conflict its existing protocol syntax. An example of where this occurs is using FTP and NTP, there's likely others where this is true. Also allows for the possibilities of issues with PMTUD (Path MTU Discovery), where it completes the TCP 3-way handshake successfully but then proceeds to hang when data is transferred over it as a black hole connection.

Additionally BT's Digital Voice (DV) is an example of IP-Telephony (VOIP) which is affected by address translation, so having full native dual stack is a benefit here. This thus means the address translation for IPv6 is within their own network no longer an issue. Especially important given the upcoming switch off (close down) of PTSN during December 2025 which is the year after next!

BT can correct this by enabling their current DNS server's (if they are compatible) to connect to the network with both IPv4 and IPv6. As well as configuring the service which the Smart Hubs and Home Hubs connect to, so that it is specifying both IPv4 and IPv6 IP addresses of the DNS servers.

To get a better idea checkout this article - https://en.wikipedia.org/wiki/IPv6.

To see the current situation for BT as ISP - https://test-ipv6.com/.

Re: IPv6 Not Enabled

jds340 — Sun, 12 May 2024 11:50:44 GMT

In my FTTC setup I can see 2001:4860:4860::8888 and 2001:4860:4860::8844 as the IPv6 DNS servers. But I've no idea where that setting came from.