User's Manual

3.2.5 Advanced Setup >> Static Routes
When you have more than one network on your LAN, and you want to route
certain IP addresses of network to another network, add them in the static
routes.
Destination Network / Host. The destination network is the address of the
remote network or host you to which you want to assign a static route.
Subnet Mask. The Subnet Mask determines which portion of a destination IP
address is the network portion, and which portion is the host portion.
Gateway. This is the IP address of the gateway device that allows for
connection between the Router and the remote network or host.