VPN Connection causes DNS to use wrong DNS server

Question

I have a Windows 7 PC on our company network (which is a member of our Active Directory). Everything works fine until I open a VPN connection to a customer's site.

When I do connect, I lose network access to shares on the network, including directories such as 'Application Data' that we have a folder redirection policy for. As you can imagine, this makes working on the PC very difficult, as desktop shortcuts stop working, software stops working properly due to having 'Application Data' pulled from under it.

Our network is routed (10.58.5.0/24), with other local subnets existing within the scope of 10.58.0.0/16. The remote network is on 192.168.0.0/24.

I've tracked the issue down to being DNS related. As soon as I open the VPN tunnel, all my DNS traffic goes via the remote network, which explains the loss of local resources, but my question is, how can I force local DNS queries to go to our local DNS servers rather than our customers?

The output of ipconfig /all when not connected to the VPN is below:

Windows IP Configuration

   Host Name . . . . . . . . . . . . : 7k5xy4j
   Primary Dns Suffix  . . . . . . . : mydomain.local
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : mydomain.local

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : mydomain.local
   Description . . . . . . . . . . . : Broadcom NetLink (TM) Gigabit Ethernet
   Physical Address. . . . . . . . . : F0-4D-A2-DB-3B-CA
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::9457:c5e0:6f10:b298%10(Preferred)
   IPv4 Address. . . . . . . . . . . : 10.58.5.89(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : 31 January 2012 15:55:47
   Lease Expires . . . . . . . . . . : 10 February 2012 10:11:30
   Default Gateway . . . . . . . . . : 10.58.5.1
   DHCP Server . . . . . . . . . . . : 10.58.3.32
   DHCPv6 IAID . . . . . . . . . . . : 250629538
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-14-AC-76-2D-F0-4D-A2-DB-3B-CA

   DNS Servers . . . . . . . . . . . : 10.58.3.32
                                       10.58.3.33
   NetBIOS over Tcpip. . . . . . . . : Enabled

This is the output of the same command with the VPN tunnel connected:

Windows IP Configuration

   Host Name . . . . . . . . . . . . : 7k5xy4j
   Primary Dns Suffix  . . . . . . . : mydomain.local
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : mydomain.local

PPP adapter Customer Domain:

   Connection-specific DNS Suffix  . : customerdomain.com
   Description . . . . . . . . . . . : CustomerDomain
   Physical Address. . . . . . . . . :
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 192.168.0.128(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.255
   Default Gateway . . . . . . . . . :
   DNS Servers . . . . . . . . . . . : 192.168.0.16
                                       192.168.0.17
   Primary WINS Server . . . . . . . : 192.168.0.17
   NetBIOS over Tcpip. . . . . . . . : Disabled

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : mydomain.local
   Description . . . . . . . . . . . : Broadcom NetLink (TM) Gigabit Ethernet
   Physical Address. . . . . . . . . : F0-4D-A2-DB-3B-CA
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::9457:c5e0:6f10:b298%10(Preferred)
   IPv4 Address. . . . . . . . . . . : 10.58.5.89(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : 31 January 2012 15:55:47
   Lease Expires . . . . . . . . . . : 10 February 2012 10:11:30
   Default Gateway . . . . . . . . . : 10.58.5.1
   DHCP Server . . . . . . . . . . . : 10.58.3.32
   DHCPv6 IAID . . . . . . . . . . . : 250629538
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-14-AC-76-2D-F0-4D-A2-DB-3B-CA

   DNS Servers . . . . . . . . . . . : 10.58.3.32
                                       10.58.3.33
   NetBIOS over Tcpip. . . . . . . . : Enabled

The binding order for the interfaces is as follows:

I've not configured the VPN tunnel to use the default gateway at the remote end, and network comms to nodes on both networks are fine. (i.e. I can ping any node on our network or the remote network).

I've modified the PPTP connection properties to use the DNS servers 10.58.3.32 followed by 192.168.0.16, yet the query still goes to 192.168.0.16.

Answer 1

Your VPN tunnel is between the client and the client network. Sounds like it isn't using split tunnelling, which will stop you accessing resources on your own network while the tunnel is up.

So you (or your client) need to enable split tunneling, or you need an extra network connection and customised route table to access both networks at the same time.

Answer 2

Check your DNS Settings or re-configure VPN Setup in your windows. Setup VPN on Windows 7 is not a tough task. it is easy i hope you will pick up sharply. Before setting up the setup on your windows 7 VPN, computer it is necessary that you possess a user ID and password from your VPN provider and we assume that you have it already. Step1: Click start button and type “Network and Sharing Center” on the bar to move to the said location

Step2: In the resulting window, you will notice “Change your networking settings” on the top, click “Set up a new connection or network” just below it.

Step3: “Set Up a Connection or Network” wizard will appear as a result. You have to click the third option from top, i.e. “Connect to a workplace” and then click next.

Step4: You will be asked for the mode through you, which you want to connect to VPN from among your internet connection, or directly through a dialer. If you have paid for a VPN plan from a vendor, then select “Use my Internet Connection” else click “Dial Directly”. In most cases, the first option is preferred.

Step5: The next windows would prompt you to mention the requisite credentials regarding your Internet Address and Description name. In the Internet Address, you will have to provide your VPN server’s domain name or IP address. In the Description name, you have to mention your VPN connection name that could be anything as per your choice. A better option would be to have a descriptive name. check the other options as per your suitability. Finally click Next.

Step6: In the next window, provide the User name, Password, and domain as your VPN account credentials and click Create to establish the connection. If you are in the habit of forgetting passwords, you can check on ‘remember this password’ option. However, it could also pose a threat to your security if someone else is using your computer and he/she logs in with your account.

Step7: Once you are done with all the above mentioned steps, you can test the windows7 VPN client connection you just established. Alternatively, you can also test it later on by click Close button.