Question 9
Which two subnetworks would be included in the summarized address of 172.31.80.0/20? (Choose two)
A. 172.31.17.4/30
B. 172.31.51.16 /30
C. 172.31.64.0/18
D. 172.31.80.0/22
E. 172.31.92.0/22
F. 172.31.192.0/18
Answer: D E
Explanation
From the summarized address of 172.31.80.0/20, we find the range of this summarized network:
16 bits were borrowed
Network address: 172.31.80.0
Broadcast address: 172.31.95.255
Read more on IP address summarization
Question 10
Which three IP addresses can be assigned to hosts if the subnet mask is /27 and subnet zero is usable? (Choose three)
A. 10.15.32.17
B. 17.15.66.128
C. 66.55.128.1
D. 135.1.64.34
E. 129.33.192.192
F. 192.168.5.63
Answer: A C D
Explanation
If you follow the cram table, /27 is mask 255.255.255.224. 3 bits were borrowed with value of 32. Follow the fourth octets of the addresses:
A is a usable host address.
B is classified as a network address
C is a usable host address form the subnet 0
D is a usable host address
E is a network address
F is a broadcast address