Connectivity

The first step in connecting to a remote VPN server is actually having the ability to connect outbound from the current network, whether that is from home, a coffee shop, a corporate network, or via your favorite mobile hotspot. If the outbound connection is blocked, none of the other configurations will matter.

Inbound connection--server

On the server side, connectivity can prove a bit more difficult. The OpenVPN server needs to either reside directly on the public network, or port-forwarding rules need to be applied to deliver the traffic to the correct system. All servers used across the general Internet will require some form of routable or public IP address.

I will cover both a simple public address case in addition to the slightly more complicated port-redirection case. It is good to keep in mind that many corporate networks will seldom place the VPN server directly on the public Internet. Instead, they will usually use multiple layers of firewalls, intrusion detection system...