Cisco 7604 User Manual

37-11
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 37 Configuring DHCP Snooping
Configuring DHCP Snooping
This example shows how to enable the DHCP option-82 on untrusted port feature:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# ip dhcp snooping information option allow-untrusted
Router#(config)
Enabling DHCP Snooping MAC Address Verification
With DHCP snooping MAC address verification enabled, DHCP snooping verifies that the source MAC
address and the client hardware address match in DHCP packets that are received on untrusted ports. The
source MAC address is a Layer 2 field associated with the packet, and the client hardware address is a
Layer 3 field in the DHCP packet.
To enable DHCP snooping MAC address verification, perform this task:
This example shows how to disable DHCP snooping MAC address verification:
Router(config)# no ip dhcp snooping verify mac-address
Router(config)# do show ip dhcp snooping | include hwaddr
Verification of hwaddr field is disabled
Router(config)#
This example shows how to enable DHCP snooping MAC address verification:
Router(config)# ip dhcp snooping verify mac-address
Router(config)# do show ip dhcp snooping | include hwaddr
Verification of hwaddr field is enabled
Router(config)#
Command Purpose
Step 1
Router(config)# ip dhcp snooping verify
mac-address
Enables DHCP snooping MAC address verification.
Router(config)# no ip dhcp snooping verify
mac-address
Disables DHCP snooping MAC address verification.
Step 2
Router(config)# do show ip dhcp snooping |
include hwaddr
Verifies the configuration.

Cisco 7604 Specifications

General

Brand	Cisco
Model	7604
Category	Network Router
Language	English