BT602E Jan. 7, 2013
1) Define IP Address.
IP (Internet Protocol) Address is a numerical label assigned to each device participating in the computer network that uses the internet protocol for communication. An IP Address serves two principal functions: host or network interface identification and location addressing. The designers of the internet protocol defined an IP address as a 32-bit number and this system, known as Internet Protocol Version 4 is still use today. However, due to enormous growth of the internet and the predicted depletion of available address, a new version of IP (IPV6), using 128-bit for the address, was developed in 1995. IPv6 was standardized as RFC 2460 in 1998, and its deployment has been on-going since the mid-2000s.
Source: http://en.wikipedia.org/wiki/IP_address
2) IP Address Classes.
In the preceding topics I introduced the concepts of IP address classes and showed how the classes related to ranges of IP addresses. Of the five classes, D and E are dedicated to special purposes, so I will leave those alone for now. Classes A, B and C are the ones actually assigned for normal (unicast) addressing purposes on IP internetworks, and therefore the primary focus of our continued attention.
As we've seen, they differ in the number of bits (and octets) used for the network ID compared to the host ID. The number of different networks possible in each class is a function of the number of bits assigned to the network ID, and likewise, the number of hosts possible in each network depends on the number of bits provided for the host ID. We must also take into account the fact that one, two or three of the bits in the IP address is used to indicate the class itself, so it is effectively "excluded" from use in determining the number of networks (though again, it is still part of the network ID).
Based on this information, we can calculate the number of networks in each class, and