User cannot connect through VPN (Windows 2008 R2)

Question

Hello,
TechNet has been a major help for some resent server and network problems our office has been having.
There is one ongoing issue that no matter how much I try to fix, it wants to be stubborn and refuse to work properly.
We have a user who has the necessary permissions to VPN using our router's IP address. Just recently, she found that she was unable to VPN. This was the beginning of our technical issues as after rebooting the router, our main server, and our QuickBooks
server, we lost internet and access to the main server. Those issues have been resolved. However, the user is still unable to VPN.
I have looked up every error code that has been presented when trying to connect to VPN (807 and 800 are the most frequent), and unfortunately, none of the solutions suggested worked. These errors occur when connecting through the WAN Miniport. I am trying
to find out if I am overlooking something.
What has been tried:
Router rebooted
Created new user in Active Directory
Deleting VPN Users group and readding to user
Changing tunneling protocol to L2TP instead of PPTP. Then, created a rule in Windows Advanced Firewall to allow UDP 1701.
Creating new VPN connection.
Confirmed with ISP that there are no issues with router
I am not extremely familiar with Windows 2008 R2 and every fix I see online is extremely in depth with not much walkthrough information.
I greatly appreciate any support anyone might be able to provide.
Thank you!

Answer 1

Hi ,
According to your description, my understanding is that the client can’t access the VPN with error code 800 and 807.
I have noticed that it failed to ping the VPN server form the client.  The VPN server should be connected from the client without VPN connection established. I suggest you to turn off firewall temporarily on both sides of client and VPN server, then
try to ping the IP address of the VPN server’s interface which is connected to extranet network.
If ping failed, there might be network connectivity problem. If ping successfully, check to see if the port is open for turning traffic. Detailed troubleshooting steps you may reference the link below:
I received error 800, which says the VPN server is unreachable:
http://technet.microsoft.com/en-us/library/cc772616(WS.10).aspx#BKMK_1
Troubleshooting commom VPN related errors:
http://blogs.technet.com/b/rrasblog/archive/2009/08/12/troubleshooting-common-vpn-related-errors.aspx
If this problem still exits, does other user successfully access the VPN? Or just specified device can’t access? Would you simply describe the deployment of the VPN, such TCP/IP settings, VPN type.
Best Regards,           
Eve Wang