In the IPv4 addressing format, The number of networks allowed under the Class C address are:
A) 214 B) 27 C) 221 D) 224This Question is asked in GATE-2012 (CS) Exam
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)