Basic Calculation

Basic Calculation

Example: 1

Which of the following is the broadcast address for a Class B network ID using the default subnet mask?
A.172.255.255.255
B.192172.16.10.255
C.255.255.0.0
D.255.255.255.255
E.172.16.255.255

Answer

Answer: D

Example: 2

Which of the following devices share the same network?
A.192.168.78.25/29
B.192.168.78.23/29
C.192.168.78.33/29
D.192.168.78.38/29
E.192.168.78.41/29

Answer

  29 bits of network = 3 bits of host.
  Hosts = 2^3 – 2 = 6.
  3 bits will support 6 hosts in each network.
  Valid Subnets = 256 – 248 = 8.
  Networks would be: 0 8 16 24 32 40 48 etc.
  IP addresses 192.168.78.33/29 and 192.168.78.38/29
  fall in the 32 network range.
  C and D are in the same network (192.168.78.32/29).

Exercise

Question 1:

Which of the following is the broadcast address for a Class A network ID using the default subnet mask?

Question 2:

Which of the following is the broadcast address for a Class C network ID using the default subnet mask?