# Configuring interfaces for Layer 2 Firewalls

The interface configuration for Single Layer 2 Firewalls and Layer 2 Firewall Clusters consists of several main steps.

1. Add the required number of Physical Interfaces.
2. Add the required number of VLAN Interfaces.
3. Add IP addresses or a traffic inspection role to the interfaces.
   - IP addresses are required for interfaces that are used for system communications.
   - Interfaces that have a traffic inspection role work transparently in the network and do not have IP addresses.
4. Select the interfaces that are used for system communications.