These are few questions in which I am facing problem Ques 1 Which of the following would make a good subnet mask for the address 190.0.46.201? a) 255.255.1.0 b) 255.255.160.0 c) 255.255.248.0 d) 255.255.4.0 Answer is (c) but I don't understand how? Is there any criteria for good subnet and bad subnet? Ques 2: What class of IP address does the subnet mask 255.128.0.0 operate on? a)A b)B c)C d)A,B or C My answer (a), books answer also (a). Ques 3: What class of IP address does the subnet mask 255.255.128.0 operate on? a)A b)B c)C d)A,B or C My answer (b), books answer also (d)? Ques 4: What class of IP address does the subnet mask 255.255.255.128 operate on? a)A b)B c)C d)A,B or C My answer (c), books answer also (d)?

School homework?

1, 160, and 4 can not be used in a subnet mask. To understand why, convert them to binary. If you still dont understand why, then you need to google more on subnetting.

Sorry, no homework questions allowed.