Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A host uses the subnet mask 255.255.255.192. How many usable host addresses exist in each 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
30
This is wrong because 30 usable hosts corresponds to /27.
B
Best answer
62
This is correct because /26 yields 64 total addresses and 62 usable hosts.
C
Distractor review
126
This is wrong because 126 usable hosts corresponds to /25.
D
Distractor review
254
This is wrong because 254 usable hosts corresponds to /24.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is mistaking the subnet mask 255.255.255.192 (/26) for 255.255.255.224 (/27) or 255.255.255.128 (/25), leading to incorrect host counts. Candidates often recall 30 hosts for /27 or 126 hosts for /25 and mistakenly apply these to /26. This error arises from confusing the number of host bits and forgetting to subtract the network and broadcast addresses. The trap causes incorrect subnet sizing and can lead to selecting wrong answers under pressure.
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 subnetworks. The subnet mask 255.255.255.192 corresponds to a /26 prefix length, meaning the first 26 bits are fixed for network identification and the remaining 6 bits are available for host addressing. This mask splits the IP address space into subnets, each with 64 total addresses. To calculate usable host addresses in a subnet, subtract the network address and broadcast address from the total addresses. For a /26 subnet, 2^6 equals 64 total addresses. Removing the 2 reserved addresses leaves 62 usable host addresses per subnet. This calculation is essential for designing IP schemes that efficiently allocate address space without waste. A common exam trap is confusing the subnet mask with similar masks like /27 or /25, which yield different host counts. In practice, Cisco devices use this subnetting logic to route traffic correctly and assign IPs. Understanding the exact host capacity per subnet ensures proper network segmentation and avoids address conflicts or shortages.
KKey Concepts to Remember
- The subnet mask 255.255.255.192 corresponds to a /26 prefix, which allocates 6 bits for host addressing within each subnet.
- Each /26 subnet contains 64 total IP addresses calculated as 2 raised to the number of host bits (2^6 = 64).
- Two IP addresses in each subnet are reserved: one for the network address and one for the broadcast address.
- The number of usable host addresses per /26 subnet is 62, derived by subtracting the reserved addresses from the total.
- Subnetting divides a network into smaller segments, improving traffic management and IP address utilization in Cisco networks.
- Confusing similar subnet masks like /25 or /27 leads to incorrect host counts and is a common exam mistake.
- Cisco routers and switches use subnet masks to determine routing boundaries and to assign IP addresses correctly.
- Calculating usable hosts requires understanding binary math and the role of network and broadcast addresses in subnetting.
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.
CCNA subnetting practice questions
Practise IPv4 subnetting, CIDR, masks, host ranges and subnet selection.
CCNA OSPF practice questions
Practise OSPF neighbours, router IDs, metrics, areas and routing-table interpretation.
CCNA VLAN practice questions
Practise VLANs, access ports, trunks, allowed VLANs and switching scenarios.
CCNA STP practice questions
Practise spanning tree, root bridge election, port roles and STP troubleshooting.
CCNA EtherChannel practice questions
Practise LACP, PAgP, port-channel behaviour and bundle requirements.
CCNA ACL practice questions
Practise standard and extended ACLs, permit/deny logic and traffic filtering.
CCNA NAT practice questions
Practise static NAT, dynamic NAT, PAT and inside/outside address translation.
CCNA DHCP practice questions
Practise DHCP scopes, relay, leases and troubleshooting.
CCNA show ip route practice questions
Practise routing-table output, longest-prefix match, AD and route selection.
CCNA show interfaces trunk practice questions
Practise trunk verification and VLAN forwarding across switches.
CCNA wireless security practice questions
Practise WLAN security, authentication and wireless architecture concepts.
CCNA IPv6 practice questions
Practise IPv6 addressing, routes, neighbour discovery and common IPv6 exam traps.
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?
The subnet mask 255.255.255.192 corresponds to a /26 prefix, which allocates 6 bits for host addressing within each subnet.
What is the correct answer to this question?
The correct answer is: 62 — The mask 255.255.255.192 corresponds to /26. That leaves 6 host bits, which means each subnet contains 64 total addresses. After excluding the network and broadcast addresses, 62 usable host addresses remain. This is a standard host-capacity question. The safest approach is to convert the mask to the prefix, determine the total addresses from the number of host bits, and then subtract the two reserved addresses.
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.
Discussion
Loading comments…
Sign in to join the discussion.