Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A subnet has the network address 192.168.20.128/26. What is the broadcast address?
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
192.168.20.159
This is wrong because that would be the end of a smaller block, not the /26 block starting at .128.
B
Best answer
192.168.20.191
This is correct because .128/26 covers .128 through .191.
C
Distractor review
192.168.20.192
This is wrong because .192 is the start of the next /26 block.
D
Distractor review
192.168.20.255
This is wrong because that would be the broadcast of the full /24, not this /26 subnet.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is selecting an address like 192.168.20.159 as the broadcast address because it appears near the subnet range. This mistake happens when candidates confuse the /26 subnet starting at 192.168.20.128 with a smaller subnet block ending at .159. Another trap is choosing 192.168.20.255, which is the broadcast for the entire /24 network, not the specific /26 subnet. Misidentifying the broadcast address leads to incorrect subnetting calculations and routing issues in real networks.
Technical deep dive
How to think about this question
Subnetting divides a larger IP network into smaller, manageable segments called subnets, each with its own network and broadcast addresses. The subnet mask determines the size of each subnet by specifying how many bits are used for the network portion versus the host portion. In this question, the /26 mask means 26 bits are fixed for the network, leaving 6 bits for host addresses, resulting in 64 IP addresses per subnet block. To find the broadcast address for a subnet, identify the range of IP addresses covered by the subnet mask. For 192.168.20.128/26, the subnet block starts at 192.168.20.128 and includes 64 addresses, ending at 192.168.20.191. The first address is the network address, and the last address is the broadcast address, which is used to send packets to all hosts within that subnet. A common exam trap is confusing the broadcast address with the last address of a smaller or larger subnet block or the broadcast of the entire classful network. For example, mistaking 192.168.20.159 as the broadcast address confuses a smaller block ending at .159 with the /26 block starting at .128. Understanding subnet boundaries and block sizes prevents this error and ensures accurate network design and troubleshooting.
KKey Concepts to Remember
- A /26 subnet mask divides the IP address space into blocks of 64 addresses, including network and broadcast addresses.
- The broadcast address is always the last IP address in the subnet block and is used to send packets to all hosts within that subnet.
- Subnetting requires calculating the block size by using 2 to the power of the number of host bits, which is 32 minus the subnet mask length.
- The network address is the first IP address in the subnet block and identifies the subnet itself, not a host.
- Incorrectly identifying the broadcast address as an address from a smaller or larger subnet block causes subnetting errors.
- Cisco devices use the broadcast address to deliver packets to all devices in the subnet, making accurate calculation critical for network communication.
- The broadcast address cannot be used as a host IP address and must be excluded from host assignments.
- Understanding subnet boundaries helps prevent routing and communication issues in segmented networks.
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?
A /26 subnet mask divides the IP address space into blocks of 64 addresses, including network and broadcast addresses.
What is the correct answer to this question?
The correct answer is: 192.168.20.191 — A /26 subnet uses blocks of 64 addresses. In plain language, the block that starts at 192.168.20.128 runs through 192.168.20.191. The first address in that block is the network address, and the last address is the broadcast address. That means the broadcast address is 192.168.20.191. This is a standard subnetting calculation. Once the block size is identified, the broadcast address is simply the last address in the block.
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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