3Com Switch 7750 Configuration Guide

628 CHAPTER 59: DHCP SNOOPING CONFIGURATION
DHCP Snooping
Configuration
Configuring DHCP
Snooping
n
■ DHCP relay agent and DHCP snooping cannot be enabled at the same time. If
you have enabled DHCP relay agent on the device, you will fail to enable DHCP
snooping.
■ The dhcp-snooping trust command and the dhcp-snooping command must
be configured at the same time; otherwise DHCP packets may be dropped in
actual networking.
Configuring DHCP
Snooping to Support
Option 82
n
Enable DHCP snooping and specify trusted ports on the switch before configuring
DHCP snooping to support Option 82.
Table 497 Configure the DHCP snooping function
Operation Command Description
Enter system view system-view -
Enable the DHCP snooping
function
dhcp-snooping Required
By default, the DHCP
snooping function is disabled
Enter Ethernet port view interface interface-type
interface-number
-
Set the port connected to a
DHCP server to a trusted port
dhcp-snooping trust Required
By default, all ports of a
switch are untrusted ports
Table 498 DHCP-snooping Option 82 support configuration tasks
Configuration task Description Related section
Enable DHCP-snooping Option 82 support Required “Enabling
DHCP-snooping
Option 82 support”
on page 629
Configure a handling policy for DHCP packets
with Option 82
Optional “Configuring DHCP
Snooping to
Support Option 82”
on page 628
“Configuring a
handling policy for
DHCP packets with
Option 82” on page
629
Configure the storage format of Option 82 Optional “Configuring DHCP
Snooping to
Support Option 82”
on page 628
“Configuring the
storage format of
Option 82” on page
630