IPv4 addresses are 32-bit numbers usually represented in dotted decimal notation and include two primary parts: the prefix of the network and the host. The following topics explain IPv4 Classic Addressing, IPv4 Dotted Decimal Notation, IPv4 Subnetting, IPv4 Variable-Length Subnet Masks, recognizing and utilizing IP version 6 address forms in Junos OS RX Sequence Services Gateway, and inet6 IPv6 Protocol Family setup. more info here
Version 4 of the Internet Protocol was designed for allocation to approx. Picture 4.3 billion addresses right now. This was considered to be a much wider address space at the start of the Internet, for which there was nothing to worry about.
The sudden growth of internet users and their widespread use has increased exponentially the number of devices needed to communicate with real and unique IP. Nearly any modern appliance produced to ease human life, such as cell phones, vehicles and other electronic appliances, is slowly needing an IPS. The number of devices (other than computers / routers) increased the market for additional IP addresses which was not previously known.
IPv4 distribution is handled internationally by the Internet Assigned Numbers Authority (IANA), in cooperation with the Assigned Names and Numbers Network Company (ICANN). IANA works closely with Regional Internet Registries which are in turn responsible for the efficient distribution of IP addresses within their territories. Five of these are RIRS. All of the IPv4 address blocks is assigned according to IANA studies. The following procedures were carried out to deal with the condition −
Private IPs − Few blocks of IPs have been designated for private usage within a LAN in order to common the need for public IP addresses.
NAT − Network Address Translation is a process that enables access to several PCs / hosts with private IP addresses utilizing one or a few public IP adresses.