H3C Technologies H3C SecPath F1000-E - Manual (Page 33)

1
DHCP Overview
This chapter includes these sections:
• Introduction to DHCP
• DHCP Address Allocation
• DHCP Message Format
• DHCP Options
• Protocols and Standards
Introduction to DHCP
The fast expansion and growing complexity of networks result in scarce IP addresses assignable to hosts.
Meanwhile, as many people need to take their laptops across networks, the IP addresses need to be
changed accordingly. Therefore, related configurations on hosts become more complex. The Dynamic
Host Configuration Protocol (DHCP) was introduced to solve these problems.
DHCP is built on a client-server model, in which a client sends a configuration request and then the server
returns a reply to send configuration parameters such as an IP address to the client.
A typical DHCP application, as shown in
Figure 1 , includes a DHCP server and multiple clients (PCs and
laptops).
Figure 1 A typical DHCP application
NOTE:
A DHCP client can get an IP address and other configuration parameters from a DHCP server on another
subnet via a DHCP relay agent. For information about the DHCP relay agent, refer to
Introduction to
DHCP Relay Agent .