3Com Switch 7750 Configuration Guide Guide

588 CHAPTER 56: DHCP SNOOPING CONFIGURATION
Figure 150 illustrates the interaction between a DHCP client and a DHCP server.
Figure 150 Interaction between a DHCP client and a DHCP server
DHCP snooping listens to the following two types of packets to retrieve the IP
addresses the DHCP clients obtain from DHCP servers and the MAC addresses of
the DHCP clients:
■ DHCP_ACK packet
■ DHCP_REQUEST packet
DHCP Snooping
Configuration
DHCP client
DHCP ser v e
r
DHCP client
DHCP client
DHCP client
DHCP ser v er
DHCP ser v e
r
DHCP
-
Request
DHCP
-
Offer
DHCP
-
ACK
DHCP
-
Renew
DHCP
-
ACK
DHCP
-
Discover
DHCP
-
Request
DHCP
-
Offer
DHCP
-
ACK
DHCP
-
Renew
DHCP
-
ACK
DHCP
-
Request
DHCP
-
Offer
DHCP
-
ACK
DHCP
-
Renew
DHCP
-
ACK
DHCP
-
Discover
DHCP client
DHCP ser v e
r
DHCP client
DHCP client
DHCP client
DHCP ser v er
DHCP ser v e
r
DHCP
-
Request
DHCP
-
Offer
DHCP
-
ACK
DHCP
-
Renew
DHCP
-
ACK
DHCP client
DHCP ser v e
r
DHCP client
DHCP client
DHCP client
DHCP ser v er
DHCP ser v e
r
DHCP
-
Request
DHCP
-
Offer
DHCP
-
ACK
DHCP
-
Renew
DHCP
-
ACK
DHCP
-
Discover
DHCP
-
Request
DHCP
-
Offer
DHCP
-
ACK
DHCP
-
Renew
DHCP
-
ACK
DHCP
-
Request
DHCP
-
Offer
DHCP
-
ACK
DHCP
-
Renew
DHCP
-
ACK
DHCP
-
Discover
Tabl e 460 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
-