Linksys FGMM1000 - Application Settings: Port Forwarding and DMZ; Port Forwarding Configuration; DMZ Host IP Configuration

Port Forwarding
Configure your router to allow external devices use its LAN services. Port forwarding—for a single port,
multiple ports or a range of ports—sends traffic inbound on a specific port or ports to a specific device on your
network.
DMZ
Create an IP address to allow connected devices to access potentially risky external services without exposing
the network to threats.