H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – DHCP
H3C S7500 Series Ethernet Switches Chapter 4
DHCP Snooping Configuration
4-2
DHCP Server
DHCP Client
Switch A
(DHCP Snooping)
DHCP Client
DHCP Client
DHCP Client
Switch B
(DHCP relay agent)
Internet
DHCP Client
Switch A
(DHCP Snooping)
DHCP Client
DHCP Client
DHCP Client
Switch B
(DHCP relay agent)
Internet
DHCP Client
Switch A
(DHCP Snooping)
DHCP Client
DHCP Client
DHCP Client
Internet
Switch B
(DHCP relay agent)
DHCP Server
n Figure 4-1 Typical network diagram for DHCP snooping applicatio
Figure 4-2 illustrates the interaction between a DHCP client and a DHCP server.
DHCP-DISCOVER
DHCP-OFFER
DHCP-REQUEST
DHCP-ACK
DHCP client DHCP server
DHCP-REQUEST(renew)
DHCP-ACK
Figure 4-2 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:
z DHCP-ACK packet
z DHCP-REQUEST packet
4.1.2 Configuring DHCP Snooping
Follow these steps to configure the DHCP snooping function: