This page allows you to define LAN-to-LAN traffic where it otherwise would be blocked.
For example, say we have two LANs, one primary (LAN0/br0) and one secondary (LAN1/br1).
If you want devices on LAN0 to communicate with devices on LAN1 (and vice versa), you might use these settings:
On: checking this enables the rule defined on this row of the table.
Src: displays/lets you configure the (Logical) Source LAN for the rule on that row of the table.
Src Address: lets you narrow the rule to a specific IP address/set of addresses within the Src interface.
Dst: here, you specify the (logical) Destination LAN for the rule on this row of the table.
Dst Address: (optionally), narrows the rule to a specific IP address/set of addresses within the Dst interface.
Description: a free text field in which you can enter whatever you wish, such as notes, reminders.