H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – DHCP
H3C S7500 Series Ethernet Switches Chapter 3
DHCP Relay Agent Configuration
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 Note:
Request packets sent by a DHCP client fall into two categories: DHCP-DISCOVER
packets and DHCP-REQUEST packets. As DHCP servers coming from different
manufacturers process DHCP request packets in different ways (that is, some DHCP
servers process option 82 in DHCP-DISCOVER packets, whereas the rest process
option 82 in DHCP-REQUEST packets), a DHCP relay agent adds option 82 to both
types of packets to accommodate to DHCP servers of different manufacturers.
3.2 Configuring DHCP Relay Agent
3.2.1 DHCP Relay Agent Configuration Task List
Complete the following tasks to configure DHCP relay agent:
Task Remarks
Enabling DHCP Required
Configuring an Interface to Operate in DHCP Relay Agent Mode Required
Configuring DHCP Relay Agent Security Optional
Configuring Option 82 Supporting Optional
3.2.2 Enabling DHCP
Make sure to enable DHCP before you perform other DHCP relay agent-related
configurations, since other DHCP-related configurations cannot take effect with
DHCP disabled.
Follow these steps to enable DHCP:
To do… Use the command… Remarks
Enter system view
system-view
—
Enable DHCP
dhcp enable
Required
By default, DHCP is enabled
3.2.3 Configuring an Interface to Operate in DHCP Relay Agent Mode
When an interface operates in the relay mode, the interface forwards the DHCP
packets received from DHCP clients to an external DHCP server, which assigns IP
addresses to the DHCP clients.