Domain 1, Network Fundamentals, is a 20 percent block of the CCNA 200-301 exam and the foundation the other five domains build on, so it is where most candidates either build momentum or lose easy points. This practice test pulls questions from across the domain so you can find the weak spots before the real test does.
The questions below are the same validated items used in the per-topic quizzes across this series. The bank is weighted toward the heaviest clusters of sub-topics, so addressing and subnetting carry the most questions here, with the models, switching, physical layer, and virtualization topics filling out the rest. Every answer has a written explanation, and the test draws a fresh mix each time you retake it.
Question bank re-checked in October 2026 against the CCNA 200-301 v1.1 exam topics, which stay in force until February 2, 2027; Cisco’s v2.0 exam starts on February 3.
How to use this practice test
Work through every question, then read the explanation on each one, especially the ones you got right by guessing. The goal is not the score on a single run; it is to turn every explanation you did not already know into a topic you go back and study. When a question exposes a gap, follow the matching guide in the topic list below, then retake the test for a new set of questions.
Treat anything below about 85 percent as a signal to review that topic before you book the CCNA 200-301 itself. Subnetting questions in particular reward speed, so if those slow you down, drill them until the math is automatic.
Take the Domain 1 practice test
Thirty questions, drawn at random from the full Domain 1 bank and re-sampled on every retake:
Once you can clear this consistently, you have a solid grip on Network Fundamentals. Use the topic list below to shore up anything that tripped you, then move on to the other domains.
What the 42-question bank covers
Each attempt draws 30 questions from a bank of 42, so two runs almost never match and a third usually turns up items you haven’t seen. The split leans toward the sub-topics with the most ground to cover, which is why IPv4 addressing and subnetting hold more than a quarter of the bank. The last column shows how every answer was checked: worked out by hand, confirmed against Cisco or IEEE documentation, run on the GNS3 lab routers and switches this series uses for its show output, or run on a real host.
| Sub-topic | Questions | How the answers were checked |
|---|---|---|
| IPv4 addressing and subnetting | 11 | 9 worked by hand, 2 from documentation |
| Switching, devices and network designs | 7 | 2 on the lab switches, 5 from documentation |
| OSI and TCP/IP models, TCP and UDP | 6 | 6 from documentation |
| Interfaces and cabling | 6 | 2 on the lab, 4 from documentation |
| IPv6 addressing | 3 | 1 on the lab, 2 from documentation |
| Wireless | 2 | 2 from documentation |
| Power over Ethernet | 2 | 2 from documentation |
| Host IP verification (Windows, macOS, Linux) | 2 | 1 on a real host, 1 from documentation |
| Virtualization and VRFs | 2 | 1 on the lab, 1 from documentation |
| IOS CLI | 1 | 1 from documentation |
Read the table as a study plan as much as a description. Subnetting carries the most questions and it is also the only area where speed decides the result, because nine of those eleven items are arithmetic you either do in seconds or burn a minute on. The interface and switching rows hold most of the lab-checked questions, and they reward reading real output, so if those trip you, the fix is time on the CLI rather than more flashcards.
Five Domain 1 questions worked through
These five come straight from the bank, one from each of the areas that most often cost people points. Try each one before you read the answer.
To which subnet does the host 172.28.228.144/21 belong?
The answer is 172.28.224.0. A /21 mask is 255.255.248.0, so the third octet is the one that changes, and its block size is 256 minus 248, which is 8. Subnets in that octet start at multiples of 8: 216, 224, 232. The host’s third octet is 228, which falls in the block that starts at 224, so the subnet is 172.28.224.0, its broadcast address is 172.28.231.255, and the usable hosts run from 172.28.224.1 to 172.28.231.254. The trap answer, 172.28.228.0, is what you get if you treat a /21 as though it were a /24.
A switch finds the destination MAC on the same port the frame arrived on. What happens?
The switch filters the frame, which means it silently drops it. A matching entry on the arrival port means the sender and the receiver sit on the same segment behind that port (a hub or another switch, for example), so the receiver has already seen the frame. Forwarding it back out would only duplicate it. Flooding happens for unknown destinations, not known ones, which rules out the two flooding answers. The MAC address table guide walks through the forward, flood and filter decision with real switch output.
A port reads “connected a-half a-100” in show interfaces status. What does a-half tell you?
Autonegotiation fell back to half duplex, almost always because the device on the other end has its speed and duplex hardcoded. The a- prefix means the value was negotiated rather than configured. When one side is hardcoded it stops sending autonegotiation signals, so the negotiating side can still detect the speed but has no way to learn the duplex, and IEEE 802.3u tells it to assume half. If the far end is hardcoded to full duplex, the link now has a duplex mismatch, which shows up as late collisions on the half-duplex side, FCS and CRC errors and runts on the full-duplex side, and poor throughput, rather than a link that is down. Set both ends to auto, or both to the same fixed values.
A 48-port switch has a 370 W PoE budget. How many 30 W PoE+ devices can it power?
About 12, because PoE capacity is set by the power budget, not the port count. 370 W divided by 30 W is 12.3, so twelve devices that each draw the full PoE+ allocation use 360 W, and a thirteenth would push the switch past its budget and stay unpowered (show power inline shows it as power-deny). The 30 W figure is what the switch sends; a PoE+ device receives up to 25.5 W of it after cable loss. Questions like this one test whether you check the budget before promising power to every port.
Every interface on a router sits in a VRF. What does a plain show ip route display?
Nothing for those interfaces, because an interface placed in a VRF leaves the global routing table. On the lab router, both GigabitEthernet0/0 and GigabitEthernet1/0 carry the same address, 10.10.10.1/24, one in VRF RED and one in VRF BLUE, which would be impossible without VRFs. The RED table shows its copy of the subnet (the route code legend is trimmed from both outputs here):
R1# show ip route vrf RED
Routing Table: RED
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.10.10.0/24 is directly connected, GigabitEthernet0/0
L 10.10.10.1/32 is directly connected, GigabitEthernet0/0
192.168.10.0/32 is subnetted, 1 subnets
C 192.168.10.1 is directly connected, Loopback10The global table on the same router holds nothing at all:
R1# show ip route
Gateway of last resort is not setThat empty result is the point of the question. To see or test a VRF’s routes you name the VRF every time, with show ip route vrf RED and ping vrf RED 10.10.10.2. The virtualization and VRF guide builds this lab step by step.
What Domain 1 covers
Every sub-topic in this practice test has a full hands-on guide. Work through any that the test exposed as weak:
Addressing and subnetting carry the most weight. Start with IPv4 addressing and IPv6 addressing, then drill the math with subnetting by host requirements and VLSM.
The models and transport: the OSI and TCP/IP models frame everything else, and TCP versus UDP covers how data actually moves.
Switching and devices: see how switches build the MAC address table, the roles of routers, switches, and firewalls, and the network architectures they form.
The physical layer: copper versus fiber cabling, Power over Ethernet, and wireless fundamentals.
Hosts, virtualization, and the CLI: verifying IP settings on Windows, macOS, and Linux, virtualization with VMs, containers, and VRFs, reading interface status and counters, and the IOS CLI navigation shortcuts.
Where to go after Domain 1
Network Fundamentals is the foundation the other five domains build on, so it is worth getting solid here first. When you can pass this test comfortably, the CCNA 200-301 study roadmap lays out the full path through Network Access, IP Connectivity, IP Services, Security Fundamentals, and Automation, with the same mix of hands-on guides, real Cisco output, and practice questions for each.
