DHCP relieves you of some of the time-consuming tasks involved in setting up a TCP/IP network and in the daily management of that network. DHCP offers the following advantages:
IP address management – In a network without DHCP, you must manually assign IP addresses. You must be careful to assign unique IP addresses to each system and to configure each system individually. If a system moves to a different network, you must make manual modifications for that system. When DHCP is enabled, the DHCP server manages and assigns IP addresses without administrator intervention. DHCP clients can move to other networks without the necessity for manual reconfiguration because they obtain new information appropriate for the new network from a DHCP server.
Centralized network client configuration – You can create a tailored configuration for certain systems, or for certain types of systems. The configuration information is stored on the DHCP server so you do not need to log in to a system to change its configuration. You can make changes for multiple systems just by changing the information in the configuration files on the DHCP server.
Support for BOOTP clients – Both BOOTP servers and DHCP servers listen and respond to broadcasts from systems. The DHCP server can respond to requests from BOOTP clients as well as DHCP clients. BOOTP clients receive an IP address and the information needed to boot from a boot server.
Support for local systems and remote systems – BOOTP provides for the relaying of messages from one network to another network. DHCP takes advantage of the BOOTP relay feature in several ways. Most network routers can be configured to act as BOOTP relay agents to pass DHCP requests to DHCP servers that are not on the DHCP client's network because to the router, DHCP requests are indistinguishable from BOOTP requests. The DHCP server can also be configured to behave as a BOOTP relay agent if a router that supports BOOTP relay is not available.
Network booting – Instead of having to use RARP (Reverse Address Resolution Protocol) and the bootparams file, systems can use DHCP to obtain the information that is needed to boot from an boot server on the network. Because RARP booting requires that each subnet have a boot server but DHCP requests can be relayed across subnets, you can deploy fewer boot servers in your network when you use DHCP network booting.
Large network support – DHCP provides the following features that support large networks:
The deployment of DHCP servers can be centralized or decentralized.
Single DHCP servers can be configured to manage multiple physical networks that are not directly connected to the server with the help of DHCP relay agent.
ISC DHCP provides failover between DHCP servers so that when one server fails, the other will cover for it.
ISC DHCP load balancing enables more than one DHCP server to provide service at the same time.
Multithreading so the DHCP server can process many requests simultaneously.