Teleport VPN and NordVPN now blocked by Three - is this an IPv6 issue?

[Subnet]

My VPNs are ALL now not connecting. ThreeUK appear to have turned on IPv6 and now none will work - this included UniFi Teleport and NordVPN.

I have had this issue in the past with an older iPhone and called Three TEN times and on each occasion they promised to turn OFF IPv6, but never did, or simply were so clueless they couldn't.

With my latest iPhone the VPNs worked flawlessly - BECAUSE I was NOT RECEIVING an iIPv6 address.

Within the last week or so, this has changed and I am now receiving an IPv6 address in addition to the IPv4 one.

ThreeUK 'support' refuse to help, saying that there is nothing to do and I should modify the settings in my iPhone. Which as we know is incorrect - you cannot refuse an IPv6 address via the settings in iOS (whereas you can on macOS).

So I now have no access to business VPN or use of NordVPN.

Can anyone offer any help? 

[Subnet]

EDIT: a colleague has just tested access to my network via UniFi Teleport VPN using his iPhone which is on VODAFONE UK and it connects flawlessly.

He also confirms he DOES get an IPv6 address.

Confirming that this is an issue with THREE.

[Subnet]

EDIT2: NordVPN has confirmed:

"Unfortunately, the Internet Service Provider called "Three" is known for interference with our service"

[PeteG]

Hello. 

Ah, sounds like a frustrating issue to have. I haven't had any issues with VPNs my self, but I have seen some comments about issues with them. 

If you think IPV6 might be the cause of the issue, it might be worth turning IPV6 off in your settings to see if you can connect the VPNs while it's off. 

Pete.

[Subnet]

Sadly Pete, IPv6 cannot be turned off on iOS device.

If I tether my iPad (Bluetooth) to my iPhone (on cellular), then run Teleport on the iPad, it works.

Why? Because the iPad does not get handed the IPv6 address and so the Teleport VPN is not interfered with.

[PeteG]

I wasn't aware that iPhones couldn't do that. Can you change the APN address? If so, it might be worth trying the 3internet APN, instead of Three.co.uk. 

Pete.

[Subnet]

Yes Pete you can and in fact I have at this moment to restore some temporary functionality.

However, 3internet is I believe a broadband APN and so the consequence is that your iOS device will continuous poll its radios and run the battery down very fast. This was certainly the issue when I had to use this kludge on my prior iPhone.

[JonathanB]

Hi @Subnet,

That's right 3internet is intended primarily for Home Broadband, so it may not give ideal results on phones. I'm aware that our Tech teams can assign an IPv4 only profile for Broadband accounts.

I'm not completely certain if this can also be done for phone SIMs on our systems, but your best bet would be to ask to be connected with the Tech team, as IPv6 is causing interference with 3rd party services that you use.

Thanks,
Jonathan

[Subnet]

I think you failed to read my OP. The 'Tech Team' are utterly, utterly useless.  I've probably wasted 20 hours on the 'phone to India, who variously can't help, won't help, or simply have no idea what they're doing.

When I requested escalation (which in any professional ITIL-based IT business means next level support) I was passed through to 'complaints'  (who must be very busy) and who suggested they "would be happy" terminate the contract "as I wasn't satisfied" - I assume their 'script' has this down as Three's form of 'problem resolution'. Pity no-one knows anything about IT.

Why 'your systems' are unable to work correctly with IPv6 is beyond me, but it's now an industry conversation.

It appears, Jonathan, that you do have some knowledge of the Three cellular system - perhaps you can illuminate why yours, but not others', cellular systems 'interfere' with most types of VPN?