Question: I have a customer that uses a VPN connection, however it automatically configures my DNS settings to a non-existent DNS server, meaning every DNS resolution times out until the alternative is tried, which really slows down all Internet traffic.

Is there a way that I can prevent an application from overriding my DNS settings (without enabling UAC)? 

Alternatively, is there a way that I can set up some kind of local routing that says 'when a DNS request for IP address A comes in, actually use IP address B'?

I'm using Windows 8 Developer preview (but I suspect it should work the same as Windows 7).

Thanks

Answer: 
I don't believe there is a way to *prevent* it from happening, apart from statically assigning the DNS servers on the VPN connection.

To change the order in which DNS servers are queried, one is supposed to be able to change the interface binding order as per <https://superuser.com/a/314379/120267>, but that doesn't seem to affect VPN connections in my personal testing on Windows 7; I've confirmed that my VPN connection is consistently added to the top of the `HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Linkage\Bind` list, regardless of the interface binding order settings.

However, you can reset the DNS changes after the VPN connection is established.

Collecting Information
======================

Open up a command prompt (`Start` -> `Run...` -> `cmd`) and then run `netsh interface ipv4 show dnsservers`. You will see output similar to the following:

```
Configuration for interface "My VPN"
    Statically Configured DNS Servers:    11.22.33.44
                                          55.66.77.88
   ...

Configuration for interface "Local Network Connection"
    DNS servers configured through DHCP:  192.168.0.1
                                          192.168.0.2
    ...

```

You need the **interface name** for the VPN, and optionally your non-VPN connection's first **DNS server**. In this example, they are *My VPN* and *192.168.0.1*, respectively.

---

Setting It All Up
=================

Option 1: Disable VPN DNS
-------------------------

Assuming you don't need your VPN's DNS servers at all, you can simply run the following in the command prompt:

```
netsh interface ipv4 delete dnsservers name="<Interface Name>" address=all validate=no

Eg: netsh interface ipv4 delete dnsservers name="My VPN" address=all validate=no

```

If you run `netsh interface ipv4 show dnsservers` again, you will see that the DNS servers associated with the VPN have been removed; your non-VPN connection's DNS servers will be used to resolve hostnames.

---

Option 2: Supplement VPN DNS
----------------------------

If you need your VPN's DNS servers to resolve intranet hostnames, you can run the following in the command prompt:

```
netsh interface ipv4 add dnsservers name="<Interface Name>" address=<Non-VPN DNS server> index=1 validate=no

Eg: netsh interface ipv4 add dnsservers name="My VPN" address=192.168.0.1 index=1 validate=no

```

In this case, `netsh interface ipv4 show dnsservers` will show that your non-VPN connection's first DNS server has been added to the top of the list of your VPN's DNS servers. It will be used to resolve hostnames first, and if unsuccessful, fall back to using your VPN's regular DNS servers.
Can you check the status of the 'Use default gateway on remote network' checkbox. This is found by opening the properties of your VPN connection and go to Networking tab and select either TCP/IP v4 or TCP/IP V6 and then select properties and then advanced.
This may be enabled which could mean that all internet traffic is routed over the VPN connection.it is not always possible to disabled this and still do what you want with the VPN, but it can be disabled, it might speed up internet access. 

If that doesn't help, there is a DNS tab there and you could try adding your DNS servers there. I have tried this, but I would expect these settings to override the automatic settings.