UGC NET CS 2006 Dec-paper-2
May 23, 2024Question 4607 – 2011 June UGC NET Paper 1
May 24, 2024Question 4294 – IP-Adress
What is the correct subnet mask to use for a class-B address to support 30 Networks and also have the most hosts possible ?
Correct Answer: D
Question 6 Explanation:
→ In class-B addressing NID’s are having 16-bits and host IDs are having 16 bits.
Step-1: Given data, to support for 30 networks is required. So number of bits taken from host ID to uniquely identify each of these network is (log 30/ log 2) i.e. 5-bits.
Step-2: NID’s are required for network is 21 bits and host id is 11-bits.
Step-3: Subnet mask of a network have NID as all 1’s and Host ID as all 0’s.
Network subnet mask is : 11111111. 11111111. 11111000. 00000000
Decimal representation of above subnet mask is : 255.255.248.0
255 . 255 . 255 . 0
255 . 255 . 192 . 0
255 . 255 . 240 . 0
255 . 255 . 248 . 0