Dynamic Host Configuration Protocol Server Configuration
DHCP provides automatic allocation of reusable network addresses on a Transmission
Control Protocol/Internet Protocol (TCP/IP) network. Without DHCP, IP addresses must be
manually entered on each computer or device that is connected to the network. Automatic
allocation dramatically reduces administration and user error.
DHCP can also distribute other configuration parameters such as DNS and WINS server
addresses and domain names. The system requesting an IP address and configuration
parameters is known as the DHCP client. The system that automatically allocates the IP
addresses is known as the DHCP server.
442 Chapter 14: Configuring Access VPNs
Any Security Appliance (version 5.2 or later) provides both DHCP server and DHCP client
functionality. As a DHCP server, the Security Appliance provides hosts protected by the
firewall with the network parameters necessary for them to access the enterprise or corporate
network. As a DHCP client, the Security Appliance can obtain its own IP address and
network mask and optionally a default route from the DHCP server.
NOTE Because the DHCP client does not know the IP address of the DHCP server, the
initial DHCP requests are broadcast to every host on the network segment. Instead of
deploying a DHCP server on every network segment, you can configure your IOS router
to forward the DHCP requests to a single DHCP server by using the ip helper-address
command.