Setting up VPN on the DD-WRT firmware is an intermediate tutorial due to complex configurations and security settings. For those who doesn't already know what PPTP (Point-to-Point Tunneling Protocol) is; PPTP allows you to connect securely from a remote location (such as your office, home, or school) to a LAN (Local Area Network) designated at another location, such as your workplace/office.

Note: PPTP has some security flaws and is considered deprecated. An alternative you may find just as easy is OpenVPN.

To setup a VPN through PPTP, login to your web GUI (http://192.168.1.1) and navigate to Services > VPN where you will see under PPTP Server, disabled by default. Select Enable and fill in the following information accordingly.