What is an IP address?
“IP Address” means Internet Protocol address, and each device that is connected to a network (such as the Internet) has one.
An IP address is similar to your phone number. Your phone number is a unique set of numbers that identifies your phone so that other people can call you. Similarly, an IP address is a unique set of numbers that identifies your computer so you can send and receive data with other computers.
Currently, most IP addresses consist of four sets of numbers, each separated by a period. 192.168.1.42 is an example of an IP address.
How the IP address works
The IP is designed to work on a dynamic network. This means that the IP must work without a central directory or monitor, and that it can not depend on existing specific links or nodes. IP is an offline protocol that is datagram oriented. Therefore, each packet must contain the source IP address, the destination IP address and other data in the header to be delivered successfully.
Combined, these factors make IP an unreliable best effort delivery protocol. Error correction is handled by higher level protocols instead. These protocols include TCP, which is a connection-oriented protocol, and UDP, which is a connectionless protocol.
There are two versions of IP in use today, IPv4 and IPv6.
The original IPv4 protocol is still used today on the Internet and in many corporate networks. However, the IPv4 protocol only allowed 2 32 addresses. This, together with the way in which the addresses were assigned, led to a situation in which there would not be enough unique addresses for all devices connected to the Internet.
IPv6 was developed by the Internet Engineering Task Force (IETF) and formalized in 1998. This update substantially increased the available address space and allowed 2128 addresses. In addition, there were changes to improve the efficiency of IP packet headers, as well as improvements in routing and security.
IPv4 addresses are actually 32-bit binary numbers, which consist of the two sub-addresses (identifiers) mentioned above that, respectively, identify the network and the server of the network, with an imaginary limit that separates them. An IP address is, as such, usually shown as 4 octets of numbers from 0 to 255 represented in decimal form instead of binary form.
For example, address 18.104.22.168 represents the 32-bit binary number 10101000.11010100.11100010.11001100.
The binary number is important because that will determine what kind of network the IP address belongs to.
An IPv4 address is typically expressed in dotted decimal notation, with every eight bits (octets) represented by a number from one to 255, each separated by a period. An example of an IPv4 address would look like this: 192.168.17.43
IPv4 addresses are made up of two parts. The first numbers in the address specify the network, while the last numbers specify the specific host. A subnet mask specifies which part of an address is the part of the network and which part is directed to the specific host.