Consider three machines M, N, and P with IP addresses 100.10.5.2, 100.10.5.5,…
2019
Consider three machines M, N, and P with IP addresses 100.10.5.2, 100.10.5.5, and 100.10.5.6 respectively. The subnet mask is set to 255.255.255.252 for all the three machines. Which one of the following is true?
- A.
M, N, and P all belong to the same subnet
- B.
Only M and N belong to the same subnet
- C.
Only N and P belong to the same subnet
- D.
M, N, and P belong to three different subnets
Attempted by 143 students.
Show answer & explanation
Correct answer: C
Key idea: A 255.255.255.252 subnet mask (/30) creates subnets with 4 IP addresses each (block size = 4).
Subnet blocks in the last octet are: .0–.3, .4–.7, .8–.11, etc.
100.10.5.2 falls in the .0–.3 subnet (network .0, usable .1 and .2, broadcast .3).
100.10.5.5 and 100.10.5.6 both fall in the .4–.7 subnet (network .4, usable .5 and .6, broadcast .7).
Therefore, the two addresses 100.10.5.5 and 100.10.5.6 are in the same subnet, while 100.10.5.2 is in a different subnet.
Final answer: Only the machines with addresses 100.10.5.5 and 100.10.5.6 belong to the same subnet.