Configure DHCP on a Cisco router or switch

Configure DHCP on a Cisco router or switch

To begin, connect the router’s Ethernet port to a switch,and connect the switch to a laptop, which will serve as the DHCP client.

To configure Cisco IOS DHCP, follow these steps, which include sample commands:

Step1) Configure an IP address on the router’s Ethernet port, and bring up the interface. (On an existing router, you would have already done this.)

Router(config)# interface ethernet0/0
Router(config-if)#ip address 1.1.1.1 255.0.0.0
Router(config-if)# no shutdown

Step2) Create a DHCP IP address pool for the IP addresses you want to use.

Router(config)# ip dhcp pool mypool

Step3) Specify the network and subnet for the addresses you want to use from the pool.

Router(dhcp-config)# network 1.1.1.0 /8   

Step4) Specify the DNS domain name for the clients.

Router(dhcp-config)#domain-name mydomain.com

Step5) Specify the primary and secondary DNS servers.

Router(dhcp-config)#dns-server 1.1.1.10 1.1.1.11

Step6) Specify the default router (i.e., default gateway).

Router(dhcp-config)#default-router 1.1.1.1

Step7) Specify the lease duration for the addresses you’re using from the pool.

Router(dhcp-config)#lease 7

Step8) Exit Pool Configuration Mode.

Router(dhcp-config)#exit
Source: http://www.techrepublic.com/article/configure-dhcp-on-a-cisco-router-or-switch/5690240