Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A host is configured with IP address 172.16.100.222/27. 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
172.16.100.191
This is wrong because .191 is the broadcast of the previous /27 block.
B
Best answer
172.16.100.223
This is correct because .222 is in the 192–223 /27 block.
C
Distractor review
172.16.100.224
This is wrong because .224 is the network address of the next block.
D
Distractor review
172.16.100.255
This is wrong because .255 is not the broadcast of this /27 subnet.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is selecting the broadcast address from an adjacent subnet block instead of the correct one. For example, choosing 172.16.100.191 as the broadcast address is tempting because it is close numerically, but it actually belongs to the previous /27 subnet block (160–191). Another common mistake is confusing the network address of the next block (172.16.100.224) with the broadcast address. This confusion arises because subnet boundaries increment in fixed blocks, and the broadcast address is always the highest IP in the current subnet, not the start of the next one. Understanding subnet block ranges is critical to avoid this trap.
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 defined range of IP addresses determined by the subnet mask. A /27 subnet mask means 27 bits are used for the network portion, leaving 5 bits for host addresses. This results in 32 IP addresses per subnet block, including the network and broadcast addresses. The subnet mask 255.255.255.224 reflects this division, where the last octet increments in steps of 32 (0, 32, 64, etc.). To determine the broadcast address for a host IP like 172.16.100.222/27, you first identify which subnet block the IP belongs to. The blocks for /27 subnets in the fourth octet are 0–31, 32–63, 64–95, 96–127, 128–159, 160–191, 192–223, and 224–255. Since 222 falls within the 192–223 block, the broadcast address is the last IP in that block, 172.16.100.223. This address is reserved for broadcast traffic to all hosts in that subnet. A common exam trap is confusing the broadcast address with the network address or the broadcast address of adjacent subnets. For example, 172.16.100.191 is the broadcast for the previous subnet block (160–191), and 172.16.100.224 is the network address of the next block. Misidentifying these addresses can lead to incorrect subnetting answers and network misconfigurations. Cisco routers and switches rely on accurate subnet and broadcast address calculations to forward traffic correctly and maintain network segmentation.
KKey Concepts to Remember
- Subnetting divides an IP network into smaller address blocks by borrowing bits from the host portion to create subnet masks.
- A /27 subnet mask corresponds to 255.255.255.224, which creates subnets with 32 IP addresses each, including network and broadcast addresses.
- The broadcast address for a subnet is always the highest IP address in that subnet's range, used to send packets to all hosts within that subnet.
- To find the broadcast address, identify the subnet block containing the host IP, then select the last IP address in that block.
- Cisco devices use subnet masks to determine the network and broadcast addresses, which are critical for routing and packet delivery.
- Incorrectly identifying the broadcast address can cause communication failures or misrouting in Cisco networks.
- Hosts configured with an IP address must be aware of their subnet’s broadcast address to properly send broadcast traffic.
- Subnet boundaries are defined by the subnet mask, and understanding these boundaries is essential for IP addressing and network design.
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.
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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?
Subnetting divides an IP network into smaller address blocks by borrowing bits from the host portion to create subnet masks.
What is the correct answer to this question?
The correct answer is: 172.16.100.223 — A /27 uses address blocks of 32. In practical terms, the fourth-octet ranges are 0–31, 32–63, 64–95, 96–127, 128–159, 160–191, 192–223, and 224–255. Since 222 falls inside the 192–223 block, the broadcast address is the last address in that block, which is 172.16.100.223. This is a classic subnet-boundary question because it tests whether you can place a host in the correct block and then identify the final address in that block as the broadcast.
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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