Configuration of DHCP feature on the Pix firewall.
The Dynamic Host Configuration Protocol (DHCP) daemon must be enabled to listen for DHCP client requests.
When the PIX Firewall acts as a DHCP server, PIX provides network configuration parameters to DHCP clients. Dynamically assigned IP addresses are an example for network configuration parameters. These configuration parameters provide a DHCP client with the networking parameters necessary to access an enterprise network and network services like the Domain Name System (DNS).
The DHCP server on PIX does not support failover. If a DHCP server runs on PIX, the MAC address-to-IP address bindings are not replicated to the secondary standby unit. Therefore, if the secondary standby unit becomes active, the secondary unit can hand out IP addresses that the primary unit has handed out already.
Unfortunately, PIX has limited functionality in the context of DHCP. You cannot configure DHCP reservation on PIX. Routers and servers can handle DHCP reservation. PIX can only work as:
DHCP client support within the PIX Firewall is designed for use within a small office, home office (SOHO) environment using a PIX Firewall that is directly connected to a DSL or cable modem that supports the DHCP server function.
* The PIX Firewall DHCP client can only be enabled on the outside interface.