VPN not working since AV uninstall

Alwayslearningmore
Alwayslearningmore used Ask the Experts™
on
I have an urgent issue and can't seem to find an answer. 

The client has server 2012 A software VPN is setup.  Which is no longer working. 
server had GDATA installed which I removed and reinstalled webroot. Then restarted the server.

 Since this I have not been able to get the VPN working again. I have tried running removal tools for Webroot, Gdata and disabled the windows firewall, however, no success at all. Still no VPN access. 

Does anyone have any suggestions ? 

Error is

The network connection between your computer and the VPN server could not be established because the remote server is not responding. This could be because one of the network devices (e.g, firewalls, NAT, routers, etc) between your computer and the remote server is not configured to allow VPN connections. Please contact your Administrator or your service provider to determine which device may be causing the problem.
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Top Expert 2015

Commented:
What kind of software VPN is it?  It will be helpful to know if there is logging on the software (there should be) so we can determine if it's the port being blocked or the service is not running, etc.  If the VPN software run as service did you check to ensure that it's running?  Screenshot of the error message will help as well.

Author

Commented:
VPN Type: L2TP/IPsec with pre-shared key

Error is

The network connection between your computer and the VPN server could not be established because the remote server is not responding. This could be because one of the network devices (e.g, firewalls, NAT, routers, etc) between your computer and the remote server is not configured to allow VPN connections. Please contact your Administrator or your service provider to determine which device may be causing the problem.

It was working for 6 months prior to this change including this morning.

The registry is set to to 2
as per

https://support.microsoft.com/en-au/help/926179/how-to-configure-an-l2tp-ipsec-server-behind-a-nat-t-device-in-windows

Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\PolicyAgent
Top Expert 2015

Commented:
Ok, let's start troubleshooting from inside the router/firewall.  Can you replicate the connection from inside the router/firewall?  This way we can eliminate that it's not a router/firewall issue.

I assume that you have a port forwarded from your router/firewall for this service to your server.  If so, you should be able to use a laptop or desktop from inside and try to replicate the VPN connection from within.

Also, is the associated VPN service running on the server?

Have a look at this article, a lot of things to check but let's try from the two above to isolate the problem first.  Then we can go through this article.

https://support.microsoft.com/en-ca/help/325034/how-to-troubleshoot-a-microsoft-l2tp-ipsec-virtual-private-network-cli

Author

Commented:
using can you see me I can see the VPN port is open.
I can't do anything with the router as it is a managed Cisco router from the client's ISP.
Top Expert 2015

Commented:
Are you able to get a machine, install the VPN client then try to VPN into the Server 2012 from inside the network?

We are trying to eliminate the Cisco router from the troubleshooting.

Author

Commented:
I don't understand, How can you VPN into a server on the internal network ?
Top Expert 2015

Commented:
Ok, you will need to be more descriptive with your answers or we will be going in circle for a long time.

Since you mentioned about software VPN and L2TP/IPsec it sounded like you're using Windows VPN.  I said "I assume that you have a port forwarded from your router/firewall for this service to your server.  If so, you should be able to use a laptop or desktop from inside and try to replicate the VPN connection from within."

Did I assume correctly?  In other words, is your 2012 the VPN server or is the Cisco router the VPN server?

Also, is the associated VPN service running on the server?

Author

Commented:
Sorry it is very late.

The 2012 server is the VPN server.
The Cisco router just has the VPN ports forwarded.

I have never created a VPN from within a network and did not know this would work ? I have only ever setup VPN's from external sources. s
Top Expert 2015

Commented:
Not a problem.  This will work because the VPN server is the Windows 2012 server.  So you should be able to replicate the connection from a machine within the network for testing.

On the other hand, if the VPN is handled by the Cisco router then you will need to test from the WAN side of the router.  In any case, the troubleshooting strategy is to eliminate the router/firewall as being the problem.
Top Expert 2016

Commented:
Is the vpn setup using routing and remote access?  Perhaps removing the role and starting anew will fix this?

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