CCST IP Addressing & Subnetting 5 — Questions and Answers
Question 1: Which IPv4 address block is used for testing and documentation purposes only (TEST-NET)?
- 192.0.2.0/24 (Correct answer)
- 192.168.0.0/16
- 198.51.100.0/24
- 203.0.113.0/24
Correct answer: 192.0.2.0/24
192.0.2.0/24 is designated by RFC 5737 as TEST-NET-1, reserved for documentation and example use.
Question 2: A router interface is configured with IP address 10.1.1.1/30. How many usable hosts can connect to this link?
- 2 (Correct answer)
- 4
- 6
- 1
Correct answer: 2
A /30 subnet has 4 addresses total: 1 network, 2 hosts, and 1 broadcast — making it ideal for point-to-point links.
Question 3: What is the result of ANDing a host IP address with its subnet mask?
- The network address (Correct answer)
- The broadcast address
- The gateway address
- The host portion of the address
Correct answer: The network address
ANDing an IP address with its subnet mask zeroes out the host bits, revealing the network address.
Question 4: A packet destined for 10.5.3.255 on a 10.5.3.0/24 network will be sent to which type of address?
- Directed broadcast (Correct answer)
- Unicast
- Multicast
- Anycast
Correct answer: Directed broadcast
10.5.3.255 is the directed broadcast address for the 10.5.3.0/24 subnet, delivered to all hosts on that subnet.
Question 5: Which supernet correctly summarizes the subnets 192.168.4.0/24 through 192.168.7.0/24?
- 192.168.4.0/22 (Correct answer)
- 192.168.4.0/23
- 192.168.0.0/22
- 192.168.4.0/21
Correct answer: 192.168.4.0/22
Four consecutive /24 subnets (4–7) can be summarized as a single /22 block starting at 192.168.4.0.
Question 6: What is the valid host range for the subnet 192.168.100.128/26?
- 192.168.100.129–192.168.100.190 (Correct answer)
- 192.168.100.128–192.168.100.191
- 192.168.100.129–192.168.100.191
- 192.168.100.130–192.168.100.190
Correct answer: 192.168.100.129–192.168.100.190
The /26 block .128–.191 has network address .128 and broadcast .191, leaving .129 through .190 as usable hosts.
Question 7: Which IPv4 address is an example of a Class A address?
- 10.0.0.1 (Correct answer)
- 172.16.0.1
- 192.168.1.1
- 224.0.0.1
Correct answer: 10.0.0.1
Class A addresses range from 1.0.0.0 to 126.255.255.255; 10.0.0.1 falls within this range.
CCST IP Addressing & Subnetting 5
Which IPv4 address block is used for testing and documentation purposes only (TEST-NET)?