Packet Guardian is an easy to use captive portal for wired or wireless networks. It works in conjunction with a local DNS and DHCP server to redirect clients to a registration page where they can log in or register as a guest to gain access to a network. The configuration provides a lot of customization to fit any environment.
The DHCP server needs to be able to read and write to Packet Guardian's database to read device registration status and write lease information for the web interface. pg-dhcp is one such DHCP server.