Question

How many 1s (ones) are present in the subnet mask of 255.255.255.252?

Select one:

a. 31

b. 28

c. 30

d. None of the given options

e. 29

Answer 1

Answer- c.30

ou have 11111111.11111111.11111111.11111100(B) as the subnet mask, which leaves two bits for the host address, 2^2 is 4, so 4 possible addresses. Since you can't use all zeros (network id) and you can't use all 1s (broadcast message) you have (bits^2) - 2 => (2^2) - 2 => 2 usable addresses. This may or may not be cut down by your router, which would be one usable address for your computer. My guess is you're stuck with this because of this is how your ISP does things.

255.255.255.252 = 11111111.11111111.11111111.11111100