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Network Configuration—IPv6Today, everyone knows that the internet is running out of IP addresses. In fact, thecurrent infrastructure of the internet is running over legacy IP (aka IPv4) protocolthat was not designed for such wide-spread and complicated use (for example,IPv4 was not designed to run in a refrigerator).The original design of Internet Protocol (IPv4) is not efficient for today's networks.And even worse, we are running out of IPv4 addresses in a few years!Several methods were introduced to reduce the usage of IP addresses in theinternet including:• Classless Interdomain Routing (CIDR): This introduced the death of classfuladdressing (for example Class A, B, C) by a new subnetting method which isnot limited, unlike the classful method.• Network Address Translation (NAT): Using NAT you do not need to usepublic IP addresses on your internal hosts.Using CIDR subnets and NAT only helped IPv4 to live a few years longer, but wasnot the ultimate cure to the problem. Besides the addressing issues, there were otherproblems with IPv4 which could not be easily solved. These issues includethe following:• The size of internet routing tables was growing rapidly and this forcedbackbone providers to upgrade their networking gears.• The IPv4 was very inefficient for high throughput links and did not supportQoS by nature.Back in the early 90s, IETF had started a workgroup to solve the deficiencies of the IPprotocol. In 1995, the IETF published the initial drafts of IPv6 as the next generationIP. Since then, the protocol has matured enormously and been implemented in manyoperating systems.