Cisco IOS Cookbook, 2nd Edition

Defining DHCP Configuration Options

Problem

You want to dynamically deliver configuration parameters to client workstations.

Solution

You can configure a wide variety of DHCP parameters for configuring client workstations:

Router1#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Router1(config)#ip dhcp pool ORAserver
Router1(dhcp-config)#host 172.25.1.34 255.255.255.0
Router1(dhcp-config)#client-name bigserver
Router1(dhcp-config)#default-router 172.25.1.1 172.25.1.3
Router1(dhcp-config)#domain-name oreilly.com
Router1(dhcp-config)#dns-server 172.25.1.1 10.1.2.3
Router1(dhcp-config)#netbios-name-server 172.25.1.1 
Router1(dhcp-config)#netbios-node-type h-node
Router1(dhcp-config)#option 66 ip 10.1.1.1 
Router1(dhcp-config)#option 33 ip 192.0.2.1 172.25.1.3 
Router1(dhcp-config)#option 31 hex 01
Router1(dhcp-config)#lease 2
Router1(dhcp-config)#exit
Router1(config)#end
Router1#

Discussion

The strength of DHCP is its ability to configure client workstations from a centralized location using DHCP options. It greatly reduces costs if workstations can dynamically learn all of their configuration options instead of having to send a technician to every desk.

DHCP can assign default routes, domain names, name server addresses, and WINS server addresses, to name just a few. RFC 2132 defines a large number of standard configurable options, and includes provisions for further vendor-specific options. However, in reality most networks only use a small subset of these ...