FYI : IPv6 Prevented VPN Connection

Anvil_Iron · ‎07-07-2023

My wife uses VPN for work and one day she wasn't able to connect. I checked the router (Zyxel NR5103E) web-config and noticed the Primary/Secondary DNSv6 server addresses info were present which weren't before.

I tried disabling IPv6 in the WAN and LAN settings but internet service stopped.

I then enabled manual APN mode and changed from 3internet to Three.co.uk and restarted the router. After restart, the IPv6 info was N/A and the VPN was able to connect. VPN also connected when APN was set to 3internet with manual APN enabled.

The strange thing was when APN Manual Mode was disabled and router reset, IPv6 info was displayed. It looks like the router was obtaining IPv6 and IPv4 info from Three if manual APN mode is disabled. This could be the PDP Type being set to IPv4/IPv6 automatically by Three where as in manual APN mode, I have it set to IPv4 only.

NG · ‎07-17-2023

Update: Anvil_Iron is the man!!!

To add a little detail to help the more ignorant like me:

First, log in to the hub from a browser ideally on your laptop (or I guess phone), not the hub app. (ie, 192.168.1.1/login, logging in as admin)

1) under top-right burger menu-->Network Settings-->Broadband-->Cellular APN, I set to manual so it ended up as follows:

And under Burger menu-->Network Settings-->Home Networking-->Lan Setup, click on the 1st APN setting in the list (on the right-hand side where you click to edit), then

I then rebooted the hub, confirmed settings remained as above, and rebooted my devices (including network switch). Audio player and speaker when connected to my network switch do show up on hub app both under Wi-Fi and LAN as expected.

... AND I'M NOW LISTENING TO MY PINK FLOYD ALBUM ONCE AGAIN!!!!!

Thanks again Anvil_iron!!

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andrewbrisland · ‎02-16-2024

This has worked for my issue also !! it must be something to do with IP4/IP6 but I have no idea why !! I don't know what effect making these changes has on other connections through the Hub but my work will be happy to know I can connect ! still no idea why it changed all of a sudden today, will anyone from Three give us an explanation ??

RyanBeves · ‎11-14-2023

just wanted to say thank you for this post.. I’ve been on live chat for 2 hours with three and they didn’t have a clue about this problem.. finally managed to fix it because of this post so thank you

jonalx7 · ‎10-07-2023

Thanks for that info

It’s worked a treat sorted the issue in minutes.

456 · ‎10-09-2023

Hi. Have your download speeds been affected?

JonathanB · ‎07-17-2023

Thanks @NG, I'm sure the step by step and screenshots will be really helpful for other community members. 🙂

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zoobill · ‎07-11-2023

Thanks for posting this fix!

I only realized that my router firmware had been upgraded when my wifi printer became inaccessible and the network map section of my pc audit software (Belarc Advisor) output had become blank!

I used your method to disable IPv6 and now I can see my home network again. Many thanks!

JonathanB · ‎07-07-2023

Thanks for sharing this @Anvil_Iron, I'll pass the feedback on.

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JonathanB · ‎07-07-2023

We're also looking into some issues with connecting to some VPN services in general. I'm not sure this is necessarily the same problem, but can you let me know which VPN provider she was having difficulties connecting to?

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Anvil_Iron · ‎07-07-2023

Hi Jonathan, It's GlobalProtect by Palo Alto Networks.

bhavinnp · ‎07-09-2023

Hi Guys,

Thanks Anvil_Iron , this fixed my issues since the update of the new firmware. I had Major issues with wired LAN devices. My Eufy, Philips Hue and wifi mesh APs all stopped working. I wasn’t sure what what was the issues as my setup is complex. I noticed that wired devices didn’t all get ip addresses from dhcp, had to manually setup an ip on wifi mesh for the disc to connect. Was wired as even directly connecting the some devices to the Lan port didn’t work but a laptop did. I also noticed a lag on my vpn for work (Meraki teleworker device). The Nintendo Switch didn’t want to connect to Wi-Fi.