A firewall can act as a DHCP server, assigning IP addresses dynamically to requesting clients. A firewall DHCP server returns its own interface address as the client's default gateway. The interface subnet mask is returned for the client to use as well.
Cisco firewalls support up to 256 active clients at any one time. (The Cisco PIX 501 supports either 32, 128, or 256 clients, depending on the user license.)
No provisions are available for configuring static address assignments. A firewall can manage only dynamic address assignments from a pool of contiguous IP addresses.
A firewall can also act as a DHCP relay, forwarding DHCP requests received on one interface to DHCP servers found on another interface. DHCP relay ...