Check Point UTM-1 Edge User Manual page 194

Configuring Network Settings
The UTM-1 appliance supports the following VLAN types:
•
Tag-based
In tag-based VLAN you use one of the gateway's ports as a 802.1Q VLAN trunk,
connecting the appliance to a VLAN-aware switch. Each VLAN behind the trunk is
assigned an identifying number called a "VLAN ID", also referred to as a "VLAN
tag". All outgoing traffic from a tag-based VLAN contains the VLAN's tag in the
packet headers. Incoming traffic to the VLAN must contain the VLAN's tag as well, or
the packets are dropped. Tagging ensures that traffic is directed to the correct VLAN.
Figure 20: Tag-Based VLAN
180 Check Point UTM-1 Edge User Guide