A split tunnel allows some traffic to be directed through your VPN, whilst allowing the rest of the traffic to be unaffected and go through your normal network route. This may be useful when you want to leave the rest of your internet connection unaffected, in terms of speed or bandwidth. However, it also may be useful if you need to keep access to other assets on your local network, whilst connecting to a specific asset on the VPN - giving you the best of both worlds.

Unfortunately this article assumes you have a basic knowledge of OpenVPN. Many Mac users will find themselves using an app called Tunnelblick (which is free and open source) to connect to OpenVPN servers, or create them. For more information, please Google TunnelBlick OpenVPN.

In this instance, configuration files can be edited by opening up the main window of Tunnelblick, right-clicking on the VPN configuration and clicking the Edit this OpenVPN configuration file.

Step 1

Open the config file - this can vary, depending on whether you use TunnelBlik or another application to connect to your VPN.

If you're using Tunnelblik, open up the main window of Tunnelblick, right-click on the VPN configuration and click 'Edit this OpenVPN configuration file'.

Step 2

Input the following two lines at the beginning of the config (1.2.3.4 is just a placeholder in this example):

route-nopull
route 1.2.3.4

Step 3

Find out the IP address for the websites you want to be routed via the VPN.

You can do this by typing in a web address in an IP finder service, such as Network Tools, which should show you the IP records of any given domain.

If you want to find out the IP address of your own machine, you may use ipify.org; this website tells you your current IP address. To find out the IP address, you can copy and paste the following command into the Terminal app and press return:

curl 'https://api.ipify.org?format=json'

The IP address is to be found in the reply, for example (if 1.2.3.4 was your IP address):

{"ip":"1.2.3.4"}%

Step 4

Input the IP address in the config file.

Say if the service we want to access on the VPN has an IP of 1.2.3.4 - we would use this in our config file.

So change the second line of the text we inserted at the start of the tutorial, adjusting the IP to the desired entry:

route-nopull
route 1.2.3.4

Step 5

Save the config file, restart your OpenVPN client and then connect using the edited configuration file.

You shall see that if you check xmyip.com will return the VPN IP address while all other websites will be routed via the normal ISP connection. You can test this on xmyip.com, and it should return your IP? address.