Trouble with connection to work VPN

Called for the 3rd time today with same issues. Apparently the ping is too high and T-Mobile drops packets as data is sent. The tech explained that bc the IP address changes frequently, TMOBILE is not compatible with working through a VPN. So, the problem is going to continue and they don't have a solution. She was amazingly honest and I will be keeping my service for my home with them but for office I'm getting a new provider.

We are using the same and I am having issues with SIM cards.  We need to fix this.  We are looking to move over 100 phones to Verizon if they do not get this fixed.  We are also using IKE2 and we are not about to change protocol based on a single carrier.

For anyone out there using Microsoft VPN technology; DirectAccess, which uses HTTPS tunneling, works fine over T-Mobile internet. However Microsoft Always On VPN, configured to use IKEv2, is blocked. Just got off half an hour with tech support, they can't unblock it. 

I'm going to try and get our Always On VPN approved for SSTP, which is not as secure as IKEV2 but uses HTTPS tunneling as well, which should work.

I installed an Eero Pro mesh network, and now the VPN works without a problem.

Checking the box for  Allow local (LAN) access when using VPN (if configured) in the Cisco preferences worked for me. I also selected the "First_Time_Connect" server (don't know if that's a universal option). I'm online now via T-mobile for the first time in two weeks.

Devanl wrote:

Happy to report that T-mobile replaced my modem with a new model and the problem appears to be fixed!

Did they replace with the same type of 5G gateway or a completely different model? Do you mind sharing what gateway works now for you? Having a similar issue but I cannot even connect to my VPN. TIA.

Happy to report that T-mobile replaced my modem with a new model and the problem appears to be fixed!

This is a known issue to us, everyone with T-Mobile’s Home Internet service and the Cisco VPN Client have WEIRD issues, and have only been able to switch Internet providers, as absolutely no solutions were provided by T-Mobile, in both cases, almost like they don’t know what the issue is.  Last one was about a month ago 7/2022, and she switched Internet providers and all is well.

It’d be nice if like a second level support could assist at T-Mobile, but no such luck in troubleshooting on their end.

It appears to be a router issue, maybe a memory leak, blocked ports, or bad routing?

I noticed one time that all DNS queries did not resolve DNS hostnames (FQDN acutally), via the VPN connection.

Devanl wrote:

Does anyone at TMobile read these?

This community is mostly made up of T-mobile customers like you, with sparse T-Mobile moderation.  We are usually not privy to the internal information within T-Mobile, to accurately answer questions such as you have asked.

Your best option is to contact T-Mobile directly.

https://www.t-mobile.com/isp/faq

¿Dónde puedo obtener ayuda para la configuración o el diagnóstico de problemas?

Si estás teniendo problemas con la conexión, el gateway o la app, ¡podemos ayudarte! Go here for more information: Troubleshooting Support. You can also reach out to us on social media or call the T-Mobile Home Internet support team 24x7 at 1-844-275- 9310 to get help with your service.

There are a few threads that might address your issue:

VPN Issues with T-Mobile Home internet when using Cisco Anyconnect

Firmware update has fixed my Cisco AnyConnect VPN issues with T-mobile home internet

Does anyone at TMobile read these?