Figure 14-5 Network diagram for DHCP-snooping implementation
For different DHCP Clients, DHCP Server provides three IP address assigning methods:
(1)
Manually assign the IP address: Allows the administrator to bind the static IP address to
the specific Client (e.g.: WWW Server) via the DHCP Server.
(2)
Automatically assign the IP address: DHCP Server assigns the IP address without an
expiration time limitation to the Clients.
(3)
Dynamically assign the IP address: DHCP Server assigns the IP address with an
expiration time. When the time for the IP address expired, the Client should apply for a
new one.
The most Clients obtain the IP addresses dynamically, which is illustrated in the following
figure.
Figure 14-6 Interaction between a DHCP client and a DHCP server
(1)
DHCP-DISCOVER Stage:
The Client broadcasts the DHCP-DISCOVER packet to find
the DHCP Server.
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