- You have class B Address with 100 Subnets & 500 usable hosts. What is the subnet mask?
Answer:
Class B is N.N.H.H
100 Subnets means 2^7=128, then we need 7 bits for network
|
255.255.1111111 |
0.00000000 |
Which is 255.255.254.0
2. Given 213.105.72.0/28
What is usable subnet & host addresses the above
address can provide?
Answer:
/28 means the number of 1's in the subnet mask, which is 255.255.255.240 in binary will be
Host: 2^4-2=14 usable address
Network: 2^4-2=14 usable address
3. Given 210.106.14.0/24
What is usable subnet & host addresses the above
address can provide?
Answer:
/24 means the number of 1's in the subnet mask, which is 255.255.255.0. There are 2^8=256 hosts address (254 usable addresses) & 2^0=1 Network address.
4. Given subnet mask 255.255.255.224
What is the valid IP Address from the below?
(a) 92.11.178.93
(b) 134.178.18.56
(c) 192.168.18.63
(d) 192.168.16.87
(e) 134.178.19.192
Answer:
The only way to solve this question is to check each choice.
First find out the number of host digits form the subnet mask by writing the last digit in binary as below and then compared to each of the given choices.
|
|
255.255.255.111 |
00000 |
|
|
(a) |
92.11.178. 010 |
11101 |
|
|
(b) |
134.178.18. 001 |
10111 |
|
|
(c) |
192.168.18. 001 |
11111 |
This is a Broadcast address and therefore not a valid address |
|
(d) |
192.168.16. 010 |
10111 |
|
|
(e) |
134.178.19. 110 |
00000 |
This is a Network address and therefore not a valid address |
| 
