TUN versus TAP mismatches

A common mistake when setting up a VPN based on OpenVPN is the type of adapter that is used. If the server is configured to use a TUN-style network but a client is configured to use a TAP-style interface, then the VPN connection will fail. In this recipe, we will show what is typically seen when this common configuration error is made.

Getting ready

Set up the client and server certificates using the first recipe from Chapter 2, Client-server IP-only Networks. For this recipe, the server computer was running CentOS 6 Linux and OpenVPN 2.3.11. The client was running Fedora 22 Linux and OpenVPN 2.3.11. Keep the configuration file, basic-udp-server.conf, from the Server-side routing recipe from Chapter 2, Client-server IP-only Networks.

How to do it...

1. Start the server using the configuration file, basic-udp-server.conf:

           [root@server]# openvpn --config basic-udp-server.conf
   

2. Next, create the client configuration:

           client 
           proto udp 
        ...