IPv6 addresses given but no connection

[Liam_]

The problem is that BT aren't saying what areas are affected nor how long the fix is going to take.  We would be relying on posters to say what area they are in if they have the same issue.  Another problem being, the vast majority probably don't even know IPv6 isn't working on their connection, much less what it is.  There may be a dozen or so mentions of issues like yours on here, out of a customer base of 13+ million.

[De_Carabas]

I mentioned the situation to a 'techie' at work who said that he had heard of the issue from others.  He believes he had read that it was related to a misconfiguration with QOS on some of BTs repeaters.  Whether that's the case, makes any sense at all etc I have no idea.

I am still trying to find some way of actually asking BT to look into it.  It's really not that easy to raise an issue that is anything beyond the simple.  Is it BT or is it OpenReach?  Who actually owns the bit at the exchange? 

[zzz]

It's definitely some kind of misconfiguration - we get PD and default route (via link local gateway), but no IPv6 DNS servers. Also nothing seems to be able to pass through the gateway in both directions.

I think the issue lies within BT's network equipment configuration. OpenReach is responsible for the physical infrastructure (optical links between exchanges and street cabinets, copper cables entering customer premises etc.).

[De_Carabas]

I'm not concerned about the DNS servers as it looks that no one is getting those, BT is using the IPv4 DNS servers to issue both address types.  Would also probably go with OpenDNS or Google anyway.

So, again it comes down to how to flag someone in BT who might be able to help who doesn't tell you it's not supported and suggest you subscribe to their 'tech-expert' service.

I thought I might have hit the jackpot for a while when I got a reply after commenting on a post on the BT Facebook page.  Nope, got told that IPv6 wasn't supported but I might like to try the Tech-Experts.  

[andyduk]

Ah. I am getting exactly the same issue with a smart hub and bt whole home WiFi. Not being able to disable ipv6 on my smarthub means that ipv6 websites keep timing out or in the case of android Netflix / Gmail / Facebook. With no way to switch this off on the Smarthub I'm screwed unless I pay for a new device. I've just shelled out a bt smarthub and wholehome WiFi thinking naively this would be the most sensible option. Any suggestions for a quick vdsl2 router that supports bt TV?

[jmarden]

Really wishing I had found this thread first (as opposed to last) as it might've saved me a bunch of money and a whole lot of time. Anyway, I live in Bracknell...

I gave up trying to get my SmartHub 5's IPv6 working as I was reading that it was probably to blame for the issues I was having. So I replaced it with a Draytek 2860 and I'm still having routing issues. I've posted loads of technical data on the Draytek user forums: 2860 BT IPv6 not routing

So here I am, another hand raised as someone with IPv6 issues in Bracknell.

[zzz]

Welcome to the club, @jmarden 🙂

So it seems that probably no one at BT is aware of the IPv6 issues in Bracknell and there is no way to notify "real" network support guys.

For now I have a script running on the router to remove the default IPv6 route when the PPPoE connection is established - this way devices connecting to Internet "know" that the IPv6 network is unreachable and use only IPv4.. so no timeouts. 

But it is really irritating that IPv6 network is misconfigured at some exchange in Bracknell...

[smf22]

@jmarden. Are you the user 'desc' who has posted on the Draytek forum? If so where did you get the IPv6 addresses you've used for the WAN i.e., 2A00:b1aa:b1aa:EC00:1D:AAFF:FEF0:8AE9/128?

EDIT: Looking other captures in Draytek post it appears the IPv6 addresses are an obfuscation of the real addresses substituting "b1aa:b1aa".

As far as I've seen all BT IPv6 addresses are allocated from 2a00:23c0::/27 (BTBROADBAND BTBROADBAND) and more specifically 2a00:23c0::/29 (BTBROADBAND BTBROADBAND-AGG-56) so this looks completely wrong.

What is the configuration you're using on the WAN interface? It should be using PPPoE as IPv4 is, but with a DHCPv6 client operating on the WAN to request via DHCPv6-PD (Prefix Delegation) an IPv6 address prefix from the upstream 'delegting router'.

[jmarden]

@smf22 you're absolutely right, I obfuscated the IPv6 addresses as I didn't want them out there without knowing how long I might be allocated that block for. 

The IPv4 WAN is PPPoE and I've just tried WAN DHCPv6 Client but the router didn't even get an IP.  Everything I've read online says to use IPv6 PPP mode with BT and I have just finished configuring two other sites (Reading and Brighton) without issue; both route IPv6 absolutely fine.

[smf22]

Are all three sites using a Draytek 2860 with the same firmware and configuration? If so that's a pretty clear indication that the issue is isolated to the Bracknell area.

Not sure if the Draytek has a CLI with tcpdump, but if not can you capture the traffic on the WAN as described in the Draytek How to capture Router's WAN packets FAQ? If you can do that we can check to see how the delegating router is responding to the DHCPv6-PD request from the Draytek router.