A host can be assigned IP address information either:
- Statically - The host is manually assigned the correct IP address, subnet mask, and default gateway. The DNS server IP address can also be configured.
- Dynamically - IP address information is provided by a server using the Dynamic Host Configuration Protocol (DHCP). The DHCP server provides a valid IP address, subnet mask, and default gateway for end devices. Other information may be provided by the server.
Figure 1 and Figure 2 provide static and dynamic IPv4 address configuration examples.
Statically assigned addresses are commonly used to identify specific network resources, such as network servers and printers. They can also be used in smaller networks with few hosts. However, most host devices acquire their IPv4 address information by accessing a DHCP server. In large enterprises, dedicated DHCP servers providing services to many LANs are implemented. In a smaller branch or small office setting, DHCP services can be provided by a Cisco Catalyst switch or a Cisco ISR.