Operation Manual – DHCP
H3C S3610&S5510 Series Ethernet Switches
Chapter 1 DHCP Overview
1-2
Note:
When residing in a different subnet from the DHCP server, the DHCP client can get the
IP address and other configuration parameters from the server via a DHCP relay agent.
For information about the DHCP relay agent, refer to
.
1.2 DHCP Address Allocation
1.2.1 Allocation Mechanisms
DHCP supports three mechanisms for IP address allocation.
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Manual allocation: The network administrator assigns an IP address to a client like
a WWW server, and DHCP conveys the assigned address to the client.
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Automatic allocation: DHCP assigns a permanent IP address to a client.
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Dynamic allocation: DHCP assigns an IP address to a client for a limited period of
time, which is called a lease. Most clients obtain their addresses in this way.
1.2.2 Dynamic IP Address Allocation Process
Figure 1-2
Dynamic IP address allocation process
As shown in the figure above, a DHCP client obtains an IP address from a DHCP server
via four steps:
1)
The client broadcasts a DHCP-DISCOVER message to locate a DHCP server.
2)
A DHCP server offers configuration parameters such as an IP address to the client
in a DHCP-OFFER message. The sending mode of the DHCP-OFFER is
determined by the flag field in the DHCP-DISCOVER message. Refer to
