Three blocking vpn's?

Hi all,

Today I noticed that my vpn connects but passes no traffic when I am using 3 data (mobile) so I checked 2 other vpn's to find they are all doing similar things except 1 vpn which doesn't connect at all.

I have tried this on my home network and also a different mobile network which leads me to think that its a 3uk issue.

Is anyone having a similar issue on 3?

Thanks

I tried a VPN a couple of weeks ago, but no problem except that the VPN provider only single-streamed. Which rather wrecked my basic reason for ditching the landline as I lost the speed gain.

In reply to a post by RobertoS:

I tried a VPN a couple of weeks ago, but no problem except that the VPN provider only single-streamed. Which rather wrecked my basic reason for ditching the landline as I lost the speed gain.

It can depend on the protocol, some connection oriented VPN protocols over TCP) essentially create a single lane that all traffic has to travel down. UDP orientated VPN protocols can run in parallel. Many corporate VPNs use TCP as they are operating over HTTPS to ensure they work over ISPs and some firewalls.

I'm using NordVPN with no issues here.

Thanks for the replies.

Ive tried nord and it's the same issue. Starting to wonder if it's an issue with my device or not.

In reply to a post by Hothead17:

Starting to wonder if it's an issue with my device or not.

Maybe a conflict with a security product?

Edited by jchamier (Mon 14-Dec-20 14:21:45)

I had this problem when I used 3 with AnyConnect - it turned out to be a MTU issue. Reducing the MTU to 1280 worked for me. Different VPNs will add a different overhead on the packet size, so you may need to experiment a bit.

Thanks for the replys.

Yea the work around I've found is use openvpn over tcp instead of wireguard or openvpn over udp

In reply to a post by Hothead17:

Yea the work around I've found is use openvpn over tcp instead of wireguard or openvpn over udp

I have no issues with UDP wireguard (Private Internet Access etc) with Smarty. It could also be your local network - double natting and/or MTU issues.

I am using Surfshark, Nord and Anyconnect over Three 5G without issues.

I use the 3internet APN and have my DNS queries forwarded from my modem to a local Cloudflare DNS over HTTPS server as I don't trust Three's way of monitoring traffic and prioritising stuff like Netflix.

Do optimise the MTU if you are having issues and try the 3internet APN if you are on three.co.uk APN. Try disabling IPV6 APN incase that might be causing issues - I know on my ZTE it is not a issue but on some Huawei routers the IPV6 is enabled on some Three masts and it doesn't have a public internet connection.

Edited by deleted (Wed 16-Dec-20 10:32:31)