Question

a. Explain with an example a scenario where both the class full and classless IP addressing scheme can be used to configure the IP address for the network. [5Marks

Answer 1

1]Class Full IP addresses:-

Class full IP address are into divided 5 classes:-

Class A to C =unicast addresses

Class D = Multicast addresses

Class E = reserved for future use

Explanation above Five classes

Class A:-

In a class A address, the first bit of the first octet is always ‘0’. Thus, class A addresses range from 0.0.0.0 to 127.255.255.255(as 01111111 in binary converts to 127 in decimal). The first 8 bits or the first octet denote the network portion and the rest 24 bits or the 3 octets belong to the host portion.

Ex :- 10.1.1.1

Class B:-

In a class B address, the first octet would always start with ’10’. Thus, class B addresses range from 128.0.0.0 to 191.255.255.255. The first 16 bits or the first two octets denote the network portion and the remaining 16 bits or two octets belong to the host portion.

Ex :- 172.16.1.1

Class C:-

In a class C address, the first octet would always start with ‘110’. Thus, class C addresses range from 192.0.0.0 to 223.255.255.255. The first 24 bits or the first three octets denote the network portion and the rest 8 bits or the remaining one octet belong to the host portion.

Ex :- 192.168.1.1

Class D:-

Class D is used for multicast addressing and in a class D address the first octet would always start with ‘1110’. Thus, class D addresses range from 224.0.0.0 to 239.255.255.255.

Ex :- 239.2.2.2

Class E:-

Class E addresses are reserved for research purposes and future use. The first octet in a class E address starts with ‘1111’. Thus, class E addresses range from 240.0.0.0 to 255.255.255.255.

2]Classless IP adresses:-

Classless to replace classfull addressing.

It allows the user to use VLSM or Variable Length Subnet Masks.

In classless(CIDR) subnet masks are denoted by /X.

For Ex :-

a subnet of 255.255.255.0 would be denoted by /24. To work a subnet mask in CIDR, we have to first convert each octet into its respective binary value. For example, if the subnet is of 255.255.255.0.

First Octet : - 255 has 8 binary 1's when converted to binary

Second Octet :- 255 has 8 binary 1's when converted to binary

Third Octet :- 255 has 8 binary 1's when converted to binary

Fourth Octet :- 0 has 0 binary 1's when converted to binary