IP ADDRESSES ABD SUBNET MASK

Question 1

What is the range of IP addresses?

Answer 1

• 0.0.0.0 to 255.255.255.255
• Value of decimal integer in octet must be within 0 to 255

Question 2

What is the network and host portion of IP addresses?

Answer 2

• The “Network portion” represent a groups of IP addresses ( Front Portion of Bits)
• The “Host portion” is used to uniquely define each IP
  address within that group of IP addresses

Question 3

What is a subnet mask?

Answer 3

• A subnet mask consists of a string of ‘1’s, followed by a string of ‘0’s.
• Binary number ‘1’s represent the Network portion.
• Binary number ‘0’s represent the Host portion.

Question 4

What is a Class A IP address?

Answer 4

• Class A IP addresses start with ‘0’.
• for governments throughout the world.]
• Range of NET ID -> 1 - 126
• Subnet Mask -> 255.0.0.0
• 127.x.x.x (decimal) is the highest assignable Class A address but reserved for the loopback address

Question 5

What is Class B IP address?

Answer 5

• Class B IP addresses start with ‘10’.
• Class B IP addresses are assigned to large- and medium-sized companies.
• Range of NET ID -> 128.0 – 191.255
• Subnet Mask -> 255.255.0.0

Question 6

What is Class C IP address?

Answer 6

• Class C IP addresses start with ** ‘110’**
• Class C IP addresses are assigned to groups that do not meet the qualifications to obtain Class A or B addresses.
• Range of NET ID -> 192.0 – 223.255.255
• Subnet Mask -> 255.255.255.0

Question 7

What is Class D IP address?

Answer 7

• Class D IP addresses start with ‘1110’.
• Class D addresses (also known as “Multicast Addresses”) are reserved for multicasting
• Range of NET ID -> 224 - 239
• Classes D have no Host portion.

Question 8

What is Class E IP address?

Answer 8

• Class E IP addresses start with ‘11110’.
• The IANA reserves Class E addresses for research, testing, and experimentation.
• Range of NET ID -> 240 - 255
• Classes E have no Host portion.

Question 9

How to calculate number of host addresses for class A, B and C?

Answer 9

• If the number of bits in the Host portion is n, the number of different Host Addresses =** 2^n – 2**
• There are two patterns cannot be used. All bits of the Host portion are ‘0’s (Network address). All bits of the Host portion are ‘1’s (Broadcast address).

Question 10

State the limitations of Classful IP addresses.

Answer 10

• Class A IPaddresses are very wasteful.
• Some countries do not need 16.7 million host IP addresses.

Question 11

State the advantages of Classless IP addresses.

Answer 11

Replacement of classful addressing with a more flexible
and less wasteful class scheme