Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A host uses address 192.168.5.126/25. Which address is the broadcast address for its subnet?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
192.168.5.63
This is wrong because .63 would be the broadcast of a /26 block, not the /25 block containing .126.
B
Best answer
192.168.5.127
This is correct because the lower /25 block runs from .0 through .127.
C
Distractor review
192.168.5.128
This is wrong because .128 is the network address of the upper /25 block.
D
Distractor review
192.168.5.255
This is wrong because .255 is the broadcast of the full /24, not the lower /25 block.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is mistaking the broadcast address for the entire /24 network (192.168.5.255) instead of the specific /25 subnet broadcast. Candidates often confuse the subnet boundaries, assuming the broadcast address is always .255 or the highest address in the original /24 block. Another pitfall is selecting the network address of the adjacent subnet (192.168.5.128) as the broadcast, which is incorrect because network addresses cannot be broadcast addresses. This confusion arises from not fully understanding how subnet masks split address ranges and how broadcast addresses are always the last address in the subnet.
Technical deep dive
How to think about this question
Subnetting is a fundamental concept in IP networking that divides a larger network into smaller, manageable segments called subnets. Each subnet has a network address, a range of usable host addresses, and a broadcast address. The subnet mask determines the size of the subnet by specifying how many bits are used for the network portion versus the host portion of the IP address. In this question, the subnet mask /25 means 25 bits are used for the network, leaving 7 bits for host addresses, effectively splitting a traditional /24 network into two equal halves. The /25 subnet mask (255.255.255.128) divides the 192.168.5.0/24 network into two subnets: 192.168.5.0 to 192.168.5.127 and 192.168.5.128 to 192.168.5.255. The broadcast address for each subnet is the highest address in that subnet range. Since the host IP 192.168.5.126 falls within the first subnet (0–127), the broadcast address is 192.168.5.127. This address is reserved to send packets to all hosts within that subnet. A common exam trap is confusing the broadcast address with the network address or the broadcast of the larger /24 block. For example, 192.168.5.255 is the broadcast for the entire /24 network, not the /25 subnet. Similarly, 192.168.5.128 is the network address of the second /25 subnet, not a broadcast address. Understanding how subnet boundaries and broadcast addresses are calculated is critical for Cisco CCNA exam success and practical network design.
KKey Concepts to Remember
- A /25 subnet mask divides a /24 network into two equal subnets, each containing 128 IP addresses including network and broadcast addresses.
- The broadcast address for a subnet is the highest IP address in that subnet’s range and is used to send packets to all hosts within the subnet.
- The network address is the lowest IP address in the subnet and cannot be used as a host or broadcast address.
- Hosts with IP addresses in the range 192.168.5.0 to 192.168.5.127 belong to the first /25 subnet, which has a broadcast address of 192.168.5.127.
- Hosts with IP addresses in the range 192.168.5.128 to 192.168.5.255 belong to the second /25 subnet, which has a broadcast address of 192.168.5.255.
- Confusing the broadcast address of the entire /24 network with the broadcast address of a smaller subnet is a common subnetting mistake on the CCNA exam.
- Subnetting requires understanding how to calculate subnet ranges by applying the subnet mask to the IP address and identifying network and broadcast boundaries.
- Cisco devices use subnet masks to determine whether an IP address is local or remote, impacting routing and packet forwarding decisions.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
A /25 subnet mask divides a /24 network into two equal subnets, each containing 128 IP addresses including network and broadcast addresses.
What is the correct answer to this question?
The correct answer is: 192.168.5.127 — A /25 divides the /24 into two halves: 0–127 and 128–255. In plain language, the host address 192.168.5.126 is in the lower half, which runs from .0 through .127. The last address in that block is the broadcast address, so the broadcast is 192.168.5.127. This is a classic subnetting question because it checks whether you can identify the correct block and then select the last address in that block as the broadcast address.
What should I do if I get this 200-301 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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