IPv4 is absolutely essential to the smooth functioning of the internet, and is currently the most widely used version of the internet protocol (IP). IPv4 is responsible for making sure data packages can be transmitted across the internet, and for locating servers (hosts) on the internet. Though there are two editions of internet protocol currently in use (IPv4 and IPv6) it is still IPv4 which is the most commonly used. Note that specific ranges in the IPv4 space are reserved by the authority that controls IP ranges, IANA, for purposes including for use in private networks or for multicast.
How an IP address works
Internet protocol (IP) is what facilitates communications between different devices on a network. The IP protocol gives every device on a network a unique numeric identifier in the shape of an IP address which defines where the device is on the internet. Servers on the internet will usually have a static, in other words permanent, IP address so that these devices can always be easily accessed at the same address. PCs and mobile devices are usually assigned dynamic IP addresses by the DHCP servers on the network that the devices are making use of, these dynamics addresses can easily change.
Understanding IPv4 addresses
Each IPv4 address has 32 bits, which is 4 bytes, and is written using decimal numbers to make it easy to read. There are four 8 bit segments written in decimal numbers which range from 0 to 255, each of the four segments is separated by a period. The total number of IPv4 addresses available is just over four billion.
Currently most of these IPv4 addresses are assigned, which is why an extended IP space – IPv6 – has been developed. IPv6 is a 128-bit number rather than the 32-bit number that makes up an IPv4 address. As regards to IPv4, the last eight IPv4 address blocks were assigned in 2011. Some companies are already switching from IPv4 to IPv6.