In IP Class - A addresses, the _________ byte is reserved for net

In IP Class - A addresses, the _________ byte is reserved for net
| In IP Class - A addresses, the _________ byte is reserved for network ids.

A. fourth

B. second

C. third

D. first

Please scroll down to see the correct answer and solution guide.

Right Answer is: D

SOLUTION

  • The IP address is an address having information about how to reach a host (specific host), especially outside the LAN.
  • An IP address is a 32-bit unique address having an address space of 232.
  • The 32 bit IP address is divided into five sub-classes.
  • Class A
  • Class B
  • Class C
  • Class D
  • Class E
  • The order of bits in first octet determinants the classes of IP address.
  • IPv4 address is divided into two parts.
  • Network ID
  • Host ID


Dotted decimal notation: 

Hexadecimal notation: 

 

Class A:

  • Network ID is 8 bits long
  • The host ID is 24 bits long.
  • In IP Class - A addresses, the first byte is reserved for network ids.
  • The higher-order bit of the first octet in class A is always set to zero. The remaining 7 bits in the first octet are used to determine network ID.


Class A has total of

27 – 2 = 128 – 2 = 126 Network ID

224 – 2 = 16777216 – 2 = 16777214 Host ID

[2 address is subtracted because 0.0.0.0 and 127.x.y.z are special address]

Default subnet mask for class A is 2555.x.x.x.