DHCP with Cisco Devices

Cisco devices can function as DHCP servers. They can be configured to forward requests to secondary servers should the Cisco device be unable to satisfy the request. Figure 3-3 shows the four-step process that the router participates in to provide DHCP services.



Configuring a Cisco device as a DHCP server

To configure the DHCP address pool name and enter DHCP pool configuration mode, use the following command:

Router(config)# ip dhcp pool name

The DHCP server assumes that all IP addresses in a DHCP address pool subnet are available for assigning to DHCP clients. You must specify the IP address that the DHCP server should not assign to clients. To do so, use the following command:

Router(config)# ip dhcp excluded-address low-address [highaddress]

To configure a subnet and mask for the DHCP address pool, use the following command in DHCP pool configuration mode:

Router(config-dhcp)# network network-number [mask /prefixlength]

Additional DHCP pool configuration mode commands enable you to configure additional parameters for the scope, including default gateway, domain name, DNS server addresses, Windows Internet Naming Service (WINS) server addresses, and so on.