Cisco Systems 32369 option code instance number ascii string hex string ip address, Defaults

Command Reference

option

To configure Cisco IOS Dynamic Host Configuration Protocol (DHCP) Server options, use the option DHCP pool configuration command. Use the no form of this command to remove the options.

option code [instance number] {ascii string hex string ip address}

no option code [instance number]

Syntax Description

code	Specifies the DHCP option code.
instance number	(Optional) Specifies a number from 0 to 255.
ascii string	Specifies an NVT ASCII character string. ASCII character strings that
	contain white space must be deliminated by quotation marks.
hex string	Specifies dotted-hexadecimal data. Each byte in hexidecimal character
	strings is two hexidecimal digits—each byte can be separated by a
	period, colon, or white space.
ip address	Specifies an IP address.

Defaults

The default instance number is 0.

Command Modes

DHCP pool configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 12.0(1)T.

DHCP provides a framework for passing configuration information to hosts on a TCP/IP network. Configuration parameters and other control information are carried in tagged data items that are stored in the options field of the DHCP message. The data items themselves are also called options. The current set of DHCP options are documented in RFC 2131, Dynamic Host Configuration Protocol.

Examples

The following example configures DHCP option 19, which specifies whether the client should configure its IP layer for packet forwarding. A value of 0 means disable IP forwarding; a value of 1 means enable IP forwarding. IP forwarding is enabled in the following example:

option 19 hex 01

The following example configures DHCP option 72, which specifies the World Wide Web servers for DHCP clients. World Wide Web servers 172.16.3.252 and 172.16.3.253 are configured in the following example:

option 72 ip 172.16.3.252 172.16.3.253

40Release 12.0(1)T