VPN (SonicWall) will not connect over T-mobile 5G Hotspot

jmadison wrote:

ntdriverman wrote:

I found a post about turning off IPv6 on my WiFi connection on my Windows laptop that resolved this issue for me.

The issue I was having was that from my Windows laptop, I was NOT able to VPN into my workplace using my personal hot-spot thru my iphone 12 (I’m running iOS 15.1.1) using TMOBILE.

To resolve the issue, I had to disable IPv6 on my Wireless connection on my laptop.

Do disable IPv6 on my Wireless connection on my Windows laptop I did these steps:

1. Open “Network and Internet Settings”
2. Under “Advanced Network Settings”, Click on “Change adapter options”
3. It will bring up a list of Network connections, double click on the one that says “Wi-Fi”
4. In the new dialog box, click on “Properties” bottom left, do NOT click on “Wireless Properties”
5. The next dialog box will have a list of "This connection uses the following items”
6. Scroll down in that list to find “Internet Protocol Version 6 (TCP/IPv6)”, this will be in the list after the “Internet Protocol Version 4 (TCP/IPv4)”.
7. Uncheck the box in front of "Internet Protocol Version 6 (TCP/IPv6)". Leave the IPv4 checked.
8. Hit “OK”

After I did these steps I was able to use the VPN client (in my case it is the FortiClient VPN) and I was able to successfully VPN thru my hot-spot thru my TMOBILE service.

I also went back and retested using a normal WiFi connection (thru my home network) and everything still worked in that case too.

This worked for me, thanks for the help!  I also use FortiClient through my employer and couldn't connect via my iPhone hotspot.  Disabling the IPv6 as you detailed here worked!

Score! I was also stuck using my company-supplied VPN (FortiClient) and my IT department swore up and down that it must be T-Mobil that is the problem (well it is in the end...). This finally fixed my issue after trying to figure it out on my own for months on end. Last week I was sitting in front of an empty church glomming off of their unprotected wifi signal just so I could obtain a file from my company servers. No more!