Cisco Systems 78-11741-02 manual Command, IPC-72

Configuring DHCP

DHCP Configuration Task List

Manual bindings are IP addresses that have been manually mapped to the MAC addresses of hosts that are found in the DHCP database. Manual bindings are stored in NVRAM on the DHCP Server. Manual bindings are just special address pools. There is no limit on the number of manual bindings but you can only configure one manual binding per host pool.

Automatic bindings are IP addresses that have been automatically mapped to the MAC addresses of hosts that are found in the DHCP database. Automatic bindings are stored on a remote host called a database agent. The bindings are saved as text records for easy maintenance.

To configure a manual binding, first create a host pool, then specify the IP address of the client and hardware address or client identifier. The hardware address is the MAC address. The client identifier, which is required for Microsoft clients (instead of hardware addresses), is formed by concatenating the media type and the MAC address of the client. Refer to the “Address Resolution Protocol Parameters” section of RFC 1700, Assigned Numbers, for a list of media type codes.

To configure manual bindings, use the following commands beginning in global configuration mode:

	Command	Purpose
Step 1
	Router(config)# ip dhcp pool name	Creates a name for the a DHCP Server address pool and places you
		in DHCP pool configuration mode—identified by the
		(dhcp-config)# prompt.
Step 2
	Router(dhcp-config)# host address	Specifies the IP address and subnet mask of the client.
	[mask /prefix-length]	The prefix length specifies the number of bits that comprise the
		address prefix. The prefix is an alternative way of specifying the
		network mask of the client. The prefix length must be preceded by
		a forward slash (/).
Step 3
	Router(dhcp-config)# hardware-address	Specifies a hardware address for the client.
	hardware-address type	The type value:
	or	• Indicates the protocol of the hardware platform. Strings and
	Router(dhcp-config)# client-identifier	values are acceptable. The string options are:
	unique-identifier	–	ethernet
		–	ieee802
		• The value options are:
		–	1 10Mb Ethernet
		–	6 IEEE 802
		If no type is specified, the default protocol is Ethernet.
		or
		Specifies the distinct identification of the client in dotted
		hexadecimal notation, for example, 01b7.0813.8811.66, where 01
		represents the Ethernet media type.
Step 4
	Router(dhcp-config)# client-namename	(Optional) Specifies the name of the client using any standard
		ASCII character. The client name should not include the domain
		name. For example, the name mars should not be specified as
		mars.cisco.com.

Cisco IOS IP Configuration Guide

IPC-72