A single PC can perform many tasks, but is limited to only the applications and data on that particular PC. Once a PC can connect to another PC or an entire network, however, there are many more resources such as printers, ﬁle storage, and applications available. Because of the value and utility of network connectivity, creating these connections properly will be an important part of your professional responsibilities.
IP Address Conﬁguration Methods
Because all devices on a TCP/IP network require IP address information in order to communicate, there are several methods for assigning addresses to IP hosts.
Administrators can enter static IP address information manually at each individual computer. This probably requires an administrator to visit each system individually to enter the address information. If the system moves to a different network location or otherwise requires a different address, the administrator must manually reconﬁgure the system. In a large network, conﬁguring TCP/IP manually can be very time consuming, and can be prone to errors that disrupt communication. For this reason, IP addresses are usually conﬁgured manually only on dedicated systems that require a static address, such as network routers, network-attached printers, or server systems that run network applications.
Automatic conﬁguration with DHCP:
Dynamic Host Conﬁguration Protocol (DHCP) is a network service that provides automatic assignment of IP addresses and other TCP/IP conﬁguration information on network systems that are conﬁgured as DHCP clients. DHCP requires a DHCP server computer conﬁgured with at least one active DHCP scope. The scope contains a range of IP addresses and a subnet mask, and can contain other options, such as a default gateway address or DNS server addresses. When the service is enabled, it automatically leases TCP/IP conﬁguration information to DHCP clients for a deﬁned lease period.
Automatic conﬁguration with APIPA:
Automatic Private IP Addressing (APIPA) is a feature of Windows®that enables a DHCP client computer to conﬁgure itself automatically with a random IP address in the range of 169.254.0.1 to 169.254.255.254 if there is no DHCP server available. APIPA enables DHCP clients to initialize TCP/IP and communicate with other local APIPA-conﬁgured machines, even in the absence of an active DHCP scope. APIPA addresses are not routable, so computers with APIPA addresses cannot communicate outside their local subnet. APIPA can be a useful conﬁguration method on small home networks because computers can initialize TCP/IP and connect without any administrative conﬁguration. On larger networks, however, a computer with an APIPA-range address is usually nothing more than a symptom, to the technician, of a DHCP problem that requires resolution.