1. Exercise 1
A company has applied for a class C IP address segment, but it needs to be allocated to 6 subsidiaries, and the largest subsidiary has 26 computers. Different subsidiaries must be in different network segments, then the subnet mask should be set to ().
A. 255.255.255.0
B. 255.255.255.128
C. 255.255.255.192
D. 255.255.255.224
Answer:
There are six subsidiaries, so three bits need to be borrowed from the host to divide the subnet, so the subnet mask is increased from 24 bits inherent in Class C to 27 bits, and the 27-bit mask is expressed as 255.255.255.224, so choose D.
2. Exercise 2
The subnet mask of a network segment 150.25.0.0 is 255.255.224.0, then () is a valid host address in this network segment. (choose 2 answers)
A. 150.25.0.0
B. 150.25.1.255
C. 150.25.2.24
D. 150.15.3.30
Answer:
According to the network segment and mask, the range of host addresses can be deduced:
150.25.000|00000.00000000
255.255.111|00000.00000000
The host address range is 150.25.0.1~150.25.31.254.
The first one is the network address, so it is excluded. The fourth one is not in the same network segment as 150.25.0.0, so it is excluded. The answer is BC.
3. Exercise 3
There are 32 subnets to be divided into a network segment of a class C address. Which of the following subnet masks is suitable?
A. 255.255.255.254
B. 255.255.255.240↵
C. 255.255.255.255
D. 255.255.255.248
Answer: 5 bits are needed to divide 32 subnets,