Excerpt:
Introduction to Network Layer Logical Addressing
- Communication at the network layer is host-to-host (computer-to-computer).
- A computer somewhere in the world needs to communicate with another computer somewhere else in the world.
- For this communication, we need a global addressing scheme, called “logical addressing”
- Today, IP addresses are used to provide logical addresses in the network layer of the TCP/IP protocol suite.
IPV4
- The Internet addresses are 32 bits in length; this gives us a maximum of 232 addresses.
- These addresses are referred to as IPv4 (IP version 4) addresses or simply IP addresses.
The need for more addresses, in addition to other concerns about the IP layer, motivated a new design of the IP layer called the new generation of IP or IPv6 (IP version 6).
IP. PROTOCOL AND NETWORK APPLICATIONS
- In this version, the Internet addresses are 128 bits in length; this gives us a maximum of 2128 addresses.
- 128-bit addresses give much greater flexibility in address allocation. These addresses are referred to as IPv6 (IP version 6) addresses.
- In this chapter, we first discuss IPv4 addresses, which are currently being used in the Internet. We then discuss the IPv6 addresses, which may become dominant in the future.
