VPN issues

rogerbock wrote:

I was able to solve my VPN issues using the guidance in https://amithkumarg.medium.com/resolved-t-mobile-home-internet-vpn-issue-2f5ca594c23e.  This was on a MacBook + Cisco AnyConnect.  I don't think I needed to change all of them, but I set the MTU on four network adapters to 1350:

en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1350
utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1350
utun1: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1350
utun2: flags=80d1<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1350

Assuming this is something that can be fixed at the router level, I really hope T-Mobile pays attention to this thread.  Not every user is going to be tech savvy enough to do this on their own.

I was skeptical of this, but yes, this was definitely the solution for me.  Your MTU number may vary so be sure to follow the procedure from that link.  Again, I have a mac and I use the Cisco AnyConnect software… regardless, your MTU is a hardware network adapter setting so AnyConnect isn't really the culprit.

Been fighting this issue for a couple of months. On my windows 10 laptop connected to Cisco Anyconnect VPN I had the IT administrator reduce my MTU to 1350 via this command

netsh interface ipv4 set subinterface “Network Name” mtu=1350 store=persistent 

substitute Network Name with your whatever your actual connection in.  Mine was Ethernet 2.

It worked.  I’m connected to VPN and have blazing speed.

Ragman177 wrote:

I too use GlobalProtect which worked fine for 1 day then quit. I resolved the issue by setting the MTU on the PANPG adapter to 1340. However, I am going to try your fix to see if that resolves the issue with the default packet size. I  am getting so much intermittent latency with this service that it is just not working for working from home. But it is great when it works. 

@Ragman177 

Wow -- I tried absolutely everything else that anyone suggested, but nothing worked until I did this.  I looked up what MTU is and how to find the optimal value, and 1340 was the number I came up with too.  After 2 days of non-stop obsessing, this is the first actual progress I've made.  Thank you!! 

I'm not sure that I understand the downside of this method.  Are you saying that sometimes it works and sometimes it doesn't at all? 

Anyway.. if this keeps working, then I can keep Tmobile internet, which will make me very happy.  Thanks again for mentioning it!

I was able to solve my VPN issues using the guidance in https://amithkumarg.medium.com/resolved-t-mobile-home-internet-vpn-issue-2f5ca594c23e.  This was on a MacBook + Cisco AnyConnect.  I don't think I needed to change all of them, but I set the MTU on four network adapters to 1350:

en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1350
utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1350
utun1: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1350
utun2: flags=80d1<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1350

Assuming this is something that can be fixed at the router level, I really hope T-Mobile pays attention to this thread.  Not every user is going to be tech savvy enough to do this on their own.

T-mobile home internet tech support was able to remotely downgrade my VPN firmware/software so that it works with Global Protect VPN. After the reset, I had to turn the router off, unplug it, then plug it back in after 30 seconds or so then turn it on, for it to work. The representative said that current firmware is known to have issue with Global Protect VPN and they are working on fixing that.

Thanks, this worked for me after lowering the MTU to 1300 on the GlobalProtect network adapter ("Ethernet 5" on my PC)!

This fixed it for me. I had problems using WireGuard VPN. I couldn't reach many sites and it was very slow.

https://amithkumarg.medium.com/resolved-t-mobile-home-internet-vpn-issue-2f5ca594c23e

Short version is you need to lower the “MTU” setting on your machine’s network adapter

For me on my macbook, it was the “wifi” “en0” device, either at the terminal with “sudo ifconfig en0 mtu 1350” or going to “Network Preferences > Advanced > Hardware” and manually configuring the MTU to 1350. 

TheloniusJ wrote:

Update: They did in fact end up rolling my firmware back and it is working again.

 

@FlyingDog For sure the performance is worse when connected to the VPN.  The previous several months this was always the case for me, I'd get about a 10-fold reduction in download speed and there was always massive latency.

My grey cylinder stopped working with my company just few days ago, maybe after they updated its firmware? How do I find out the firmware version?

Anyway, I just discovered using my cell phone hot spot as an initial connection helped me connect to company VPN using tmobile home internet. Anyone know why that might be? Here are the steps I used:

1. Connect my Macbook Pro to cell phone hotspot
2. Connect to VPN (GlobalProtect in my case)
3. Switch wifi connection from cell phone hotspot to T-mobile home internet
4. Wait for VPN to reconnect
5. The VPN connection is now working over T-mobile home internet

Update: They did in fact end up rolling my firmware back and it is working again.

@FlyingDog For sure the performance is worse when connected to the VPN.  The previous several months this was always the case for me, I'd get about a 10-fold reduction in download speed and there was always massive latency.

My Global Protect VPN worked for a second day so I started to feel a little better. However, there's more lag in the T-Mobile connection, which was frustrating when trying to type things over the VPN connection (Cox ping times for me are always <10ms and jitter is pretty low, too; with T-Mobile, ping times varied a lot between 35 and 80ms). I switched back to my Cox connection to get work done this afternoon as the T-Mobile latency bugged me. Note: the T-Mobile latency wasn't horrible for me. I usually find things <100ms to not be bad, but <10ms is a lot better.

I started looking at other issues with T-Mobile:

• Lack of configurability. I ultimately wanted to just replace my cable modem with it, but the software is crippled (there are other threads on that) so that you can't connect it to a home router, etc.
• They told me I could purchase landline service through the RJ-11 jack on the back, but when I tried to sign up for it, I got a different story, with most people being terribly confused. Most people thought I was talking about the T-Mobile Line Link service (which was discontinued in April, and not everyone there knew about it). They were telling me I needed to get a Line Link adapter and really didn't know about the 5G product. 
• Poor support. Sometimes I called and was told I'd get a call back in 1 or 2 hours. The people you talk to on the phone can only submit tickets and wait 24-72 hours for engineering to do something about it. They can't get a status on it, etc. I was incorrectly told to go to physical T-Mobile stores who have no ability to do anything about T-Mobile Home Internet other than call T-Mobile customer service.

To their credit, there are a few random knowledgeable people there. They did get my Global Protect VPN working finally when they did the firmware downgrade.

Ultimately, I ended up sending back the device today. I guess I'm stuck with Cox for now. Several years ago, Cox used to be stellar, but lots of things there have gone downhill while the prices constantly climb. I guess it's good to be a monopoly.