CCST Networking Questions:
1. You have an IP of 156.233.42.56 with a subnet mask of 7 bits. How many hosts and subnets are possible assuming that subnet 0 is not used?
a. 126 subnets and 510 hosts
b. 128 subnets and 512 hosts
c. 510 subnets and 126 hosts
d. 512 subnets and 128 hosts
ans. a
Explanation:
Class B network has the form N.N.H.H, the default subnet mask is 16 bits long. There is additional subnet mask of 7 bits long.
7 bits of subnet mask corresponds to (2^7)=128.
9 bits (16-7) of host addresses corresponds to (2^9-2)=512-2 = 510 hosts (note that all ones and all zeros bits are reserved).
Some times, the subnet mask is specified with the bits available in the default subnet mask. In this case the bits available in default subnet mask is 16. Therefore, total number of bits available in the subnet mask are 16+7=23. If you are given a subnet mask of 23 bits long for a class B address, it is understood that it contains the bits from the default subnet mask as well.
Checkout full question bank for CCST Networking: https://www.certexams.com/cisco/ccst-networking/exam-details.htm
1. You have an IP of 156.233.42.56 with a subnet mask of 7 bits. How many hosts and subnets are possible assuming that subnet 0 is not used?
a. 126 subnets and 510 hosts
b. 128 subnets and 512 hosts
c. 510 subnets and 126 hosts
d. 512 subnets and 128 hosts
ans. a
Explanation:
Class B network has the form N.N.H.H, the default subnet mask is 16 bits long. There is additional subnet mask of 7 bits long.
7 bits of subnet mask corresponds to (2^7)=128.
9 bits (16-7) of host addresses corresponds to (2^9-2)=512-2 = 510 hosts (note that all ones and all zeros bits are reserved).
Some times, the subnet mask is specified with the bits available in the default subnet mask. In this case the bits available in default subnet mask is 16. Therefore, total number of bits available in the subnet mask are 16+7=23. If you are given a subnet mask of 23 bits long for a class B address, it is understood that it contains the bits from the default subnet mask as well.
Checkout full question bank for CCST Networking: https://www.certexams.com/cisco/ccst-networking/exam-details.htm