Check Point UTM-1 Edge - Adding Internet Connections to Bridges

Overview
Chapter 7: Using Bridges 223
For example, if you assign the LAN and primary WLAN networks to a bridge and
disable the bridge's internal firewall, the two networks will act as a single, seamless
network, and only traffic from the LAN and primary WLAN networks to other
networks (for example, the Internet) will be inspected by the firewall. If you enable
the internal firewall, it will enforce security rules and inspect traffic between the LAN
and primary WLAN networks.
Figure 23: Bridge Firewalling