I cannot access my job's VPN from home

Called to cancel my service, because of this issue, on Monday.  Great performance off the VPN, pretty muddling on (Cisco AnyConnect).  T-Mobile tells me it's VPN Configuration and, after testing, Cisco says the issue is t-mobile.  Waiting to hear back from t-mobile tech support (tomorrow will be the 3rd business day) but don't expect to hear anything positive back.  I'll try again (and do more research) if indications are anything has changed in the future.

My PS4 was not performing well network-wise.  Got to poking around a bit on the laptop and discovered my MTU has dropped 1420 on TMO.  Puts MSS at 1380.  Was running my PS4 at 1470 MTU from the old network… dropped it to 1400 and it is much more consistent now.

Might want to tweak the VPN so it is not trying to send anything larger than that 1380 (if you can access an MTU setting).  1380 and not the full 1420 so there is headroom above the VPN’s encapsulation for additional header information as it goes through the networks.

Looks like a new major firmware release is hitting the wire.  Supposed to address VPN issues as well as some screwy 4G/5G band selection issues.This just came up in my YT feed:

That was posted earlier this week.  May take a while to trickle out to everyone, as they do the updates in phases.

I have a similar but different problem. Like you, i also have a company provided laptop and a vpn client. but my problem is dns resolution fails while on the vpn. luckily i hadn't shut off my cricket data plan yet so i'm just able to route traffic from my work machine to the cricket modem only, rather than letting the bonding router handle failover/load balancing like it does for all other traffic. i also had difficulty staying connected on ps5 to online games, so i routed that traffic through the cricket modem as well. 

IPv4 address availability is a big issue, which is why the world is going to v6 addressing. At one time, T-Mobile offered an unlimited data add-on called "VPN Total Internet" which provided a real IPv4 address, albeit firewalled. This hasn't been available for some time.  All T-Mobile IPv4 connections are heavily NATed and firewalled. 

However, I can connect to my home OpenVPN server using an OpenVPN client app on my phone. It just took some fiddling with the settings. I suggest you get with your IT folks and have them diagnose the connection IRT.

Thanks everyone!  I have not heard back from TMobile.  I am going to reach out to my IT dept and relay the info about the IPv4.  I actually recall them mentioning it a while back when I transitioned to home.  I let you know how it all works out.

Update.  Turns out the event log says I am getting an 809 error.  IT asked me to relay this to TMobile when they respond. Still hopeful. 

leechat wrote:

Update.  Turns out the event log says I am getting an 809 error.  IT asked me to relay this to TMobile when they respond. Still hopeful. 

Worst case is with the BS that T-mobile is doing with their gateway and internal networking… You could always ask your IT department to provision you on a WVD through Azure (if you have it) or they could setup you up with RDS web browser access.

leechat wrote:

Update.  Turns out the event log says I am getting an 809 error.  IT asked me to relay this to TMobile when they respond. Still hopeful. 

I'm not sure if "809 error" will help with diagnosing the issue. Error numbers are assigned by the programmer who wrote the application. You'd need to be very familiar with VPN server software your company is using to be able to decode the meaning of that number. As it is, we don't even know which of a half-dozen popular VPN protocols is being employed. The IT guy needs to provide a description of the problem (e.g. "IP Port #5534 is blocked").

Right now, the regular participants in the forum are just learning about Home Internet issues. As usual with T-Mobile, the official company line is "No worries, man. Everything is working fine" There are no online manuals available that would help us figure out what's going on.

In the end, the best solution may be to revert to cable or DSL.

P.S. The company who wrote the VPN server software should have also provided diagnostic software and procedures that can tell exactly why it's not working. In words, not codes.

leechat wrote:

I am currently working from home.  I use a company provided laptop with an always on VPN client to access my job's servers. No problem with spectrum cable. I have the brand new grey t-mobile gateway and cannot get in.  My IT guy worked with me and says it must be how the ports are provisioned.  He said to call and get level 2 support.  He wanted to know about specific ports. Did that, was on hold over an hour.  Tech I spoke with basically said they don't do ports. What?!  In fact when I gave her the port #s to look into she basically said no, thats not how it is designed. The tech I spoke with before her said WAN is blocked by default. What?! The level 2 person said that was not right. I get about 130 Mbps down and about 35 Mbos up. So speed is good.  My tvs, tablets, laptops, nintendo gaming, vivint(connect with lan cable to one of two ports on gateway) are streaming working fine. I can surf the web from the company laptop.  I can also get to my MS Teams & Outlook. But when I try to access a certain part of the network it won't connect. Level 2 tech opened a ticket. My VPN does not like this gateway for some reason. 

Any resolution?

I have the VPN issues with MS Client VPN and running out of option other than cancelling it.