7 Configuring DHCP Services

The Dynamic Host Configuration Protocol (DHCP) enables client systems to obtain network configuration information from a DHCP server each time they connect to the network. The DHCP server is configured with a range of IP addresses and other network configuration parameters that clients need.

When you configure an Oracle Linux system as a DHCP client, the client daemon, dhclient, contacts the DHCP server to obtain the networking parameters. As DHCP is broadcast-based, the client must be on the same subnet as either a server or a relay agent. If a client can't be on the same subnet as the server, a DHCP relay agent can be used to pass DHCP messages between subnets.

The server provides a lease for the IP address that it assigns to a client. The client can request specific terms for the lease, such as the duration. You can configure a DHCP server to limit the terms that it can grant for a lease. If a client remains connected to the network, dhclient automatically renews the lease before it expires. You can configure the DHCP server to provide the same IP address to a client, based on the MAC address of its network interface.

The advantages of using DHCP include the following:

• Centralized management of IP addresses

• Ease of adding new clients to a network

• Reuse of IP addresses reducing the total number of IP addresses that are required

• Reconfiguration of the IP address space on the DHCP server without needing to reconfigure each client

For more information about DHCP, see RFC 2131. Likewise, see the following manual pages:

• dhcpd(8)
• dhcp-options(5)