Created OpenVPN server: Only route DNS via VPN (markdown)

OpenVPN-server:-Only-route-DNS-via-VPN.md

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+Full article: https://github.com/pi-hole/pi-hole/wiki/Pi-hole---OpenVPN-server
+
+### Optional: Only route DNS via VPN
+
+With this setup you will force connected clients to use only the DNS provided by the VPN connection, i.e. the Pi-hole. Do this only if you don't want to tunnel **all** connections from the client thru the VPN, but only DNS queries.
+
+Edit your `/etc/openvpn/server.conf` and remove (comment) the following line:
+```
+# push "redirect-gateway def1 bypass-dhcp"
+```
+
+This works pretty much out of the box with common `client.ovpn` files, but when using the Network Manager, you will have to set an additional setting on the client side of things:
+
+![](http://www.dl6er.de/pi-hole/openVPN/local.png)
+
+You will also have to set the address of the DNS server manually in your operating system:
+
+![](http://www.dl6er.de/pi-hole/openVPN/manualDNS.png)
+
+After doing this, you should see:
+```
+pi.hole has address W.X.Y.Z (outside address of your VPN server)
+pi.hole has IPv6 address A:B:C:D:E:F (outside address of your VPN server)
+```
+
+The web interface of your Pi-hole will be visible at `http://10.8.0.1/admin/` (even with the recommended firewall configuration mentioned on another subpage)
+
+---
+## Troubleshooting
+
+If your new DNS server configuration has not been activated (try restarting the interface / system) you will see
+```
+host pi.hole
+Host pi.hole not found: 3(NXDOMAIN)
+```
+
+If you are not connected to your VPN network you will see
+```
+host pi.hole
+;; connection timed out; no servers could be reached
+```