The purpose of the dynamic host configuration
is to assign network settings centrally from a server rather than
configuring them locally on each and every workstation. A host configured
to use DHCP does not have control over its own static address. It is enabled
to configure itself completely and automatically according to directions
from the server.
If you use the NetworkManager on the client side, you do not need to configure
the client at all. This is useful if you have changing environments
and only one interface active at a time. Never use NetworkManager on a
machine that runs a DHCP server.
HINT: IBM System z: DHCP Support
On IBM System z platforms, DHCP only works on interfaces
using the OSA and OSA Express network cards. These cards are the only ones
with a MAC, which is required for DHCP's autoconfiguration
One way to configure a DHCP server is to identify each client using
the hardware address of
its network card (which is fixed in most cases), then supply that client with
identical settings each time it connects to the server. DHCP can also be
configured to assign addresses to each interested
client dynamically from an address pool set up for that
purpose. In the latter case, the DHCP server tries to assign the same
address to the client each time it receives a request, even over
longer periods. This works only if the
network does not have more clients than addresses.
DHCP makes life easier for system administrators. Any changes, even
bigger ones, related to
addresses and the network configuration in general can be implemented
centrally by editing the server's configuration file. This is much more
convenient than reconfiguring numerous workstations. Also it is much
easier to integrate machines, particularly new machines, into the network,
because they can be given an IP address from the pool. Retrieving
network settings from a DHCP server is especially useful in the case of
laptops regularly used in different networks.
A DHCP server supplies not only the IP address and the netmask, but also the
hostname, domain name, gateway, and name server addresses for the
client to use. In addition to that, DHCP allows a number of
other parameters to
be configured in a centralized way, for example, a time server from which
clients may poll the current time or even a print server.