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Understanding IP Addressing
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From its beginning as a research collaboration tool useful to a handful of students and scientists, the Internet has become a universal communication tool connecting people around the globe as never before. Individuals, businesses, and governments are making increasing demands for Internet resources. In order to accommodate this phenomenal growth, a much larger pool of unique identifiers—addresses—is required.
The most common Internet address assignment scheme in use today-IPv4 - provides the bank of routing addresses based on the size of the organization. This is referred to as classful IP addressing. Three variants of classful addressing are in common use today: Class A for extremely large organizations, Class B for large organizations, and Class C for smaller organizations.
Unforeseen limitations to classful addressing have been found as the demand for IP addresses has grown. Various workarounds have been developed to help overcome the limitations of classful addressing and accommodate the exponential growth in demand for IP addresses.. These includesubnetting, Variable Length Subnet Mask (VLSM) subnetting, , and Classless Interdomain Routing (CIDR).
Another workaround is to use reserved or private addresses within an organization and have a Network Address Translator between the public Internet and the corporate network. This method is frequently implemented as a part of an overall security plan.
Unless the growth of Internet routing tables can be controlled, whole sections of the Internet may simply disappear as Internet backbone routers are forced to drop routes because of address exhaustion and the high volume of routing information that they must process.
The long-term solution to these problems lies in the widespread deployment of IP Next Generation, known as IPng or IPv6, which provides a greatly expanded range of addresses. IPv4 addresses are 32 bits in length, whereas IPv6 is a 128-bit addressing scheme.
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