beautypg.com

Ip dhcp snooping information option – SMC Networks SMC Tiger 10/100 SMC6128PL2 User Manual

Page 634

background image

Command Line Interface

4-326

4

Command Mode

Global Configuration

Command Usage

If MAC address verification is enabled, and the source MAC address in the
Ethernet header of the packet is not same as the client’s hardware address in
the DHCP packet, the packet is dropped.

Example
This example enables MAC address verification.

Related Commands

ip dhcp snooping (4-322)
ip dhcp snooping vlan (4-324)
ip dhcp snooping trust (4-325)

ip dhcp snooping information option

This command enables the DHCP Option 82 information relay for the switch. Use
the no form to disable this function.

Syntax

[no] ip dhcp snooping information option

Default Setting

Disabled

Command Mode

Global Configuration

Command Usage

• DHCP provides a relay mechanism for sending information about the switch

and its DHCP clients to the DHCP server. Known as DHCP Option 82, it
allows compatible DHCP servers to use the information when assigning IP
addresses, or to set other services or policies for clients.

• When the DHCP Snooping Information Option is enabled, clients can be

identified by the switch port to which they are connected rather than just their
MAC address. DHCP client-server exchange messages are then forwarded
directly between the server and client without having to flood them to the
entire VLAN.

DHCP snooping must be enabled on the switch for the DHCP Option 82
information to be inserted into packets.

Example
This example enables the DHCP Snooping Information Option.

Console(config)#ip dhcp snooping verify mac-address
Console(config)#

Console(config)#ip dhcp snooping information option
Console(config)#