Question VPN issues

Tschrom

Honorable
Dec 21, 2016
63
1
10,545
Hey fellow PC users, gotta VPN problem. So I use my laptop at home to work through a VPN to my office... Well, yesterday my internet went down during a storm. It's come back up since, however now my VPN will no longer connect. Nobody else a my company is having VPN connection issues, just me. I'm wondering what might have happened that my VPN suddenly won't connect, No settings have changed with my VPN setup or anything. Internet working fine now. Just will. not. connect. Please help. I have urgent work that needs completed and no way to complete it without my VPN. I don't see how the internet going out in a storm would change anything on the ISP end or on the modem end for me either.
 

Madge67

Reputable
Sep 14, 2015
8
0
4,510
Hi - did you get this sorted????? if so how - we have exactly the same issue last week. We lost our internet and since then havent been able to get a connection to works vpn. Nobody seems to be able to sort the problem, works IT, VPN provider or the ISP - Im losing the will to live
 

Tschrom

Honorable
Dec 21, 2016
63
1
10,545
Hi, it had actually originally resolved itself for a while, but now it's back to it. And I've taken it to my company IT before, he claims there's nothing he can do and that's it's on the ISP end.

And I'm inclined to believe him since it gives me an error about NAT and not being able to connect to the far end, but if I switch to my mobile hotspot network it connects just fine. And a commercial VPN also works just fine over my ISP (tested NordVPN), but not the internal windows workstation to server VPN. And the only change I noticed in the last few days was my modem reset in the middle of the night one day (usually what happens when the ISP pushes some sort of modem or server end update. And now it no longer works. And when I contact my ISP to tell them about this, and the only change that's happened since my VPN stopped, and they swear up and down it can't possibly be them. So apparently there's an invisible road block between me and my IsP that seems to magically pop up after and ISP update, but it's not their fault. They have no idea. The only "fixes" I've found so far are time (which isn't acceptable when work needs to be done) or literally just resetting my modem and network drivers over and over again until it works again. Which usually doesn't work.
 
Hard to say. Most vpn services are using open vpn which runs similar to web sessions. This is part of the reason it is so popular. Many business vpn run things like IPSEC. This tends to be harder to get to work. There are options on most routers that allow stuff like vpn passthrough but it to a point depends on how they have configured the IPSEC at your company. VPN is kinda hard to remote troubleshoot. You need to try to see if there are logs or there a option to turn logs on so you can see at what stage of the process is it failing.
 

Tschrom

Honorable
Dec 21, 2016
63
1
10,545
Well the connection currently being used is L2TP because my IT apparently doesn't believe in security. But I've tried just about everything I can think of. Changed registry settings to no avail, reset the router to factory default (when the VPN still worked) to no avail, tried adjusting the VPN settings to no avail, set the router to route without nat, to no avail. Tried disabling and reenabling passthrough on L2TP, pptp, ipsec, ext. Nothing. Tried uninstalling and reinstalling all my Wan miniports and do a network reset, nothing. Tried hardwire to no avail. Tried other PCs on the same network, none of them will connect to the VPN.

But it connects just fine if I put my laptop on my mobile hotspot.... And as I said previously, commercial VPNs work fine.... But my ISP swears it's not them. It couldn't possibly be them, they claim. They don't block VPNs.... Well it sure as hell seems like they do block certain things.
 
I assume you can't bypass the router and connect directly to the modem.

It it likely related to the l2tp passthrough function. The reason you need this is these function are not running TCP or UDP they are running a different "protocol". NAT only can do TCP and UDP so routers have to do tricks to get the vpn to work. I am unsure how l2tp works since I never used it because it was not secure. Pretty much if the feature is turned on it should work but there maybe something strange about the way your company is doing the tunnel.

I doubt you ISP cares. The place stuff like this gets broken is internet cafe and other public hotspot becuase many are only allow TCP and UDP and many even further restrict it to ports used by the browser.