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Figure 6-11     Statically Assigning Host Addresses

Because a duplicated address affects the host operation, care must be taken not to reuse an address. When using static IP addressing, it is necessary to maintain an accurate list of the IP address assigned to each device.

Dynamic Assignment of Addresses

Because of the challenges associated with static address management, end-user devices often have addresses dynamically assigned, using DHCP.

DHCP enables the automatic assignment of addressing information such as IP address, sub-net mask, default gateway, and other configuration information. The configuration of the DHCP server requires that a block of addresses, called an address pool, be defined to be assigned to the DHCP clients on a network. Addresses assigned to this pool should be planned so that they exclude any addresses used for the other types of devices.

DHCP is generally the preferred method of assigning IP addresses to hosts on large net-works because it reduces the burden on network support staff and virtually eliminates entry errors. Another benefit of DHCP is that an address is not permanently assigned to a host but is only “leased” for a period of time. If the host is powered down or taken off the network, the address is returned to the pool for reuse. This feature is especially helpful for mobile users who come and go on a network.