- The definition of an IP address is a decimal number that defines the routing information of the Internet user. The address is composed of four sets of numbers, each separated by a decimal point.
An example of an IP address is 220.127.116.11.
A binary number that uniquely identifies a host computer connected to the Internet. The IP packet header provides an originating address field so that a host can identify itself as the originator of a packet. The IP packet header also provides a destination address field so that an originating host can identity the target host for which a packet is intended. Based on that information, the Internet routers can act to deliver the packet to the target host, which can respond to the originating host, as appropriate. All IP addresses are written in dotted decimal notation. An IPv4 address, for example, comprises 4 fields separated by dots and expressed as xxx.xxx.xxx.xxx, with each field given a value in decimal notation of 0
An identifier required for any machine to communicate on the Internet. The IP address looks something like this: 18.104.22.168—for numerical segments separated by dots. Any computer is reachable through its IP address.
An IP address is divided into a part identifying a network as belonging to a university, a government agency, or a company and another part identifying each computer in that network. The IP address is comparable to a “nonvirtual” street address with its street name and house number.
See Also: Internet Protocol.
(Internet Protocol address) The address of a device attached to an IP network (TCP/IP network). Every client, server and network device is assigned an IP address, and every IP packet traversing an IP network contains a source IP address and a destination IP address. Every IP address that is exposed to the public Internet is unique. In contrast, IP addresses within a local network use the same private addresses; thus, a user's computer in company A can have the same address as a user in company B and thousands of other companies. However, private IP addresses are not reachable from the outside world (see private IP address). Logical Vs. Physical An IP address is a logical address that is assigned by software residing in a server or router (see DHCP). In order to locate a device in the network, the logical IP address is converted to a physical address by a function within the TCP/IP protocol software (see ARP). The physical address is actually built into the hardware (see MAC address). Static and Dynamic IP Network infrastructure devices such as servers, routers and firewalls are typically assigned permanent "static" IP addresses. The client machines can also be assigned static IPs by a network administrator, but most often are automatically assigned temporary "dynamic" IP addresses via software that uses the "dynamic host configuration protocol" (see DHCP). Cable and DSL modems typically use dynamic IP with a new IP address assigned to the modem each time it is rebooted. The Dotted Decimal Address: x.x.x.x IP addresses are written in "dotted decimal" notation, which is four sets of numbers separated by decimal points; for example, 22.214.171.124. Instead of the domain name of a Web site, the actual IP address can be entered into the browser. However, the Domain Name System (DNS) exists so users can enter computerlanguage.com instead of an IP address, and the domain (the URL) computerlanguage.com is converted to the numeric IP address (see DNS). Although the next version of the IP protocol offers essentially an unlimited number of unique IP addresses (see IPv6), the traditional IP addressing system (IPv4) uses a smaller 32-bit number that is split between the network and host (client, server, etc.). The host part can be further divided into subnetworks (see subnet mask). Class A, B and C Based on the split of the 32 bits, an IP address is either Class A, B or C, the most common of which is Class C. More than two million Class C addresses are assigned, quite often in large blocks to network access providers for use by their customers. The fewest are Class A networks, which are reserved for government agencies and huge companies. Although people identify the class by the first number in the IP address (see table below), a computer identifies class by the first three bits of the IP address (A=0; B=10; C=110). This class system has also been greatly expanded, eliminating the huge disparity in the number of hosts that each class can accommodate (see CIDR). See private IP address and IP. NETWORKS VS. HOSTS IN IPV4 IP ADDRESSES Range Maximum Maximum Bits Class Networks Hosts Net/Host A 1-126 127 16,777,214 7/24 B 128-191 16,383 65,534 14/16 C 192-223 2,097,151 254 21/8 127 reserved for loopback test