OpenVPN server IP, DHCP conflict on Windows 10

chinesecooler

Hey guys, I am pretty green to OpenVPN. What I am trying to do is setting up a basic OpenVPN server on my Windows 10 PC and port forwarding on my router.

I have mostly followed the official guide without too much issue. However, when I tried to configure port warding on my router I realized that the default OpenVPN address 10.8.0.1 is not supported by my router as it's not in range of my local LAN. No biggie, I thought I would just put the server in the same subnet and just use a different range so here's how I did it.

In the Server.Ovpn I configured it as below:

ifconfig 192.168.0.230 192.168.0.231
ifconfig-pool 192.168.0.232 192.168.0.250
route 192.168.0.0 255.255.255.0
push "route 192.168.0.230"

My intention is to fix the server's IP to 192.168.0.230 and use 232 - 250 as client addresses but it keeps complaining that the IP range that I define is in conflict with my LAN IP.

At this stage, I am pretty lost. It would be great if you can shed some light. TIA!

Traffic

With a normal OpenVPN tunnel the default IP address of 10.8.0.0/24 is used because
it does not conflict with your home LAN, which is often 192.168.0.0/24, like yours.

So setup your VPN using the 10.8/24 range.

Otherwise you want to setup a bridged VPN:

However, in both cases:

NOTE: your local LAN uses the extremely common subnet address 192.168.0.x or 192.168.1.x. Be aware that this might create routing conflicts if you connect to the VPN server from public locations such as internet cafes that use the same subnet.

:arrow: Never use 192.168.0.0/24 or 192.168.1.0/24 (or other common subnets) for your OpenVPN Server LAN :!:

You are advised to change your server LAN to a more unique RFC1918 compliant subnet. f.e 192.168.143.0/24

Also, ensure IP forwarding is enabled on your server.

chinesecooler

Thanks Traffic, I knew that I was probably on the wrong track. I will give this a go.

chinesecooler

Finally got the server running on Win10 and client connected from my Android phone. However, it seems like the public IP address of my Android doesn't change to the same public IP of my server. This is weird. I have configured a lot of PPTP VPN and once you connect to them you are basically getting the server's public IP. Does OpenVPN works differently?

Traffic

chinesecooler wroteonce you connect to them you are basically getting the server's public IP. Does OpenVPN works differently?

OpenVPN does not do this "out of the box" .. you must configure it yourself .. See:
HOWTO: Routing all client traffic (including web-traffic) through the VPN

I recommend reading the entire Howto ..