Welcome to tech ritambhara
January 11, 2012
Difference between MAC Address and IP Address
June 11, 2012

Number of Network address in Class-C of Ipv4

In the IPv4 addressing format, The number of networks allowed under the Class C address are:

A) 214         B) 27         C) 221          D) 224

This Question is asked in GATE-2012 (CS) Exam
Solution:
Every class in IPv4 addressing has fixed format to specify IP – Address. Below is how the addresses are divided among the classes

Class-C IP address will have the following format

  • First 3 bits are fixed as 110.
  • Next 21 bits represent the Network-ID and last 4 bits represent the host-ID.

Since 21 bits are reserved for Network addresses. The total number of unique addresses possible in IPv4 Class-C is 221.
(The total size of Network-ID field is 24 out of which first 3 bits are fixed)

Hence, the correct answer is C)

Leave a Reply

Your email address will not be published. Required fields are marked *