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DHCP overview
The Dynamic Host Configuration Protocol (DHCP) provides a framework to assign configuration
information to network devices.
Figure 15 sho
ws a typical DHCP application scenario where the DHCP clients and the DHCP server
reside on the same subnet. The DHCP clients can also obtain configuration parameters from a
DHCP server on another subnet through a DHCP relay agent. For more information about the DHCP
relay agent, see "Configuring the DHCP relay agent."
Figure 15 A typical DHCP application
DHCP address allocation
Allocation mechanisms
DHCP supports the following allocation mechanisms:
• Static allocation—The network administrator assigns an IP address to a client, such as a
WWW server, and DHCP conveys the assigned address to the client.
• Automatic allocation—DHCP assigns a permanent IP address to a client.
• Dynamic allocation—DHCP assigns an IP address to a client for a limited period of time,
which is called a lease. Most DHCP clients obtain their addresses in this way.