Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A host uses subnet mask 255.255.255.224. How many total addresses exist in each subnet block?
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
16
This is wrong because 16 total addresses corresponds to a /28 subnet.
B
Best answer
32
This is correct because /27 yields 32 total addresses per subnet.
C
Distractor review
30
This is wrong because 30 is the usable host count, not the total address count.
D
Distractor review
64
This is wrong because 64 total addresses corresponds to a /26 subnet.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is confusing the total number of addresses in a subnet with the number of usable host addresses. Many candidates see the number 30 and assume it represents total addresses, but 30 is actually the count of usable hosts after excluding the network and broadcast addresses. This mistake often occurs because the question wording can be subtle, and candidates automatically recall usable hosts instead of total addresses. Misreading this can lead to selecting 30 instead of the correct total of 32 addresses for a /27 subnet mask.
Technical deep dive
How to think about this question
Subnetting is a fundamental concept in IP networking that divides a larger network into smaller subnetworks, or subnets, to improve routing efficiency and security. The subnet mask 255.255.255.224 corresponds to a /27 prefix length, meaning the first 27 bits are fixed for network identification and the remaining 5 bits are available for host addressing within each subnet. This allocation directly impacts the total number of addresses available in each subnet block. The total number of addresses in a subnet is calculated as 2 raised to the power of the number of host bits. For a /27 subnet mask, there are 32 total addresses (2^5 = 32). Out of these, 30 addresses are usable for hosts because one address is reserved as the network identifier and another as the broadcast address. Cisco devices and CCNA exam questions often emphasize distinguishing between total addresses and usable host addresses to avoid confusion. A common exam trap is confusing the total number of addresses with the number of usable host addresses. Candidates frequently mistake 30 usable hosts as the total count, leading to incorrect answers. In practical Cisco networking, understanding this distinction is crucial for designing IP schemes and troubleshooting subnet-related issues. The total address count affects subnet planning, while usable hosts determine device capacity within each subnet.
KKey Concepts to Remember
- A subnet mask of 255.255.255.224 corresponds to a /27 prefix length, which allocates 5 bits for host addressing within each subnet.
- The total number of addresses in a subnet is calculated as 2 raised to the number of host bits, so a /27 subnet has 32 total addresses.
- Out of the total addresses, 2 are reserved for the network and broadcast addresses, leaving 30 usable host addresses in a /27 subnet.
- Cisco networking and CCNA exam questions distinguish between total addresses and usable host addresses to test precise subnetting knowledge.
- Candidates often confuse usable host counts with total addresses, leading to common exam mistakes when calculating subnet sizes.
- Subnetting impacts IP address allocation, routing efficiency, and network segmentation, making accurate calculations essential for Cisco network design.
- Understanding subnet mask notation and its binary representation is critical for correctly determining subnet size and address ranges.
- The subnet mask directly influences how many subnets and hosts per subnet can be created within a given IP address space.
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 subnet mask of 255.255.255.224 corresponds to a /27 prefix length, which allocates 5 bits for host addressing within each subnet.
What is the correct answer to this question?
The correct answer is: 32 — The mask 255.255.255.224 corresponds to /27. In practical terms, that leaves 5 host bits, which means each subnet has 32 total addresses. Of those, 30 are usable host addresses and 2 are reserved for network and broadcast. This question specifically asks for total addresses, not usable addresses. That distinction matters because many candidates answer with the usable count automatically.
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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