VPN for specific UDP ports?

Question

My ping to DotA 2 servers (online video game) is very poor in afternoon hours. My ping usually go as high as 300ms or even more.

I tried to use OpenVPN with my dedicated server my ping decreased to about 80ms.

I'd like to route all game traffic through this server but not any other traffic though. How can I accomplish this?

I tried to use Proxifier or ProxyCap with SSH tunnel, but it didn't work unfortunately as the game uses UDP ports of 27015-27040 to communicate with the servers.

Answer 1

The easiest way to route traffic is by IP address. Find out the IP addresses of the DotA servers that you commonly access, and add routes to your gaming machine (assuming Windows) to your OpenVPN server private IP. In a command prompt with Administrator privileges:

route add <dota server ip> mask 255.255.255.255 <openvpn server private ip>

If you use the -p parameter it will make it permanent (survives a reboot).

If it isn't clear what the server IP address is, then you can route via the openvpn interface instead.

This command

netsh interfaces ipv4 show interfaces

will provide a list of interfaces in your machine. One of these is the openvpn tun/tap interface. Note its index (the idx) field.

Then add the route with the netsh command instead:

netsh interface ipv4 add route prefix=<dota ip address>/32 interface=<idx> store=active

Change store=active1 to store=persistant to get it to survive a reboot.

This will direct any traffic destined for the dota server to the openvpn box.