Network+ N10-009 Domain 2: Network Implementation — 10 practice questions with answers

Domain 2 is 20% of the CompTIA Network+ (N10-009) exam, which works out to roughly 18of the up to 90 questions on the real test. Below are study notes for the domain's objectives, then every question from our free Network+ N10-009 practice test that targets this domain, with the correct answer and the reasoning behind it. Try to answer each one before reading the explanation.

Objectives in this domain

2.1 Explain characteristics of routing technologies
2.2 Given a scenario, configure switching technologies and features
2.3 Given a scenario, select and configure wireless devices and technologies
2.4 Explain important factors of physical installations

What to focus on

Routing questions turn on a few rules. The longest prefix match wins first; when the same prefix arrives from different sources, the lowest administrative distance wins (connected 0, static 1, eBGP 20, OSPF 110, RIP 120). Know which protocols are link-state (OSPF), distance-vector (RIP), hybrid (EIGRP) and path-vector (BGP), and where NAT, PAT and first-hop redundancy (FHRP) fit.

Switching (2.2) covers VLANs and 802.1Q trunks, the native VLAN, voice VLANs, spanning tree and why a second uplink without it causes a broadcast storm, link aggregation with LACP, MTU and jumbo frames. Wireless (2.3) is about choosing channels and bands: on 2.4 GHz only channels 1, 6 and 11 avoid overlap, 5 GHz and 6 GHz offer far more room, and WPA3 and 802.1X Enterprise replace shared keys for corporate users.

Physical installation (2.4) looks practical but is tested as vocabulary: IDF and MDF, rack units and airflow, patch panels and fibre distribution panels, UPS and PDU sizing, and environmental factors such as temperature, humidity and fire suppression.

Practice questions and explanations

1. Two routers from different vendors must exchange routes inside the same organisation. Which routing protocol is an open standard that both are most likely to support?
1. A) EIGRP
2. B) OSPF
3. C) BGP
4. D) RIP version 1
Answer: B — OSPF
OSPF is an open-standard, link-state interior gateway protocol supported by virtually every vendor, making it the standard choice for multi-vendor internal routing. EIGRP is Cisco-originated, BGP is the exterior protocol used between autonomous systems on the internet, and RIPv1 is a legacy classful protocol with no modern place. (Objective 2.1)
2. A router has learned the same destination network from OSPF (administrative distance 110) and from a static route (administrative distance 1). Which route is installed in the routing table?
1. A) The OSPF route, because dynamic routes are preferred
2. B) The static route, because a lower administrative distance wins
3. C) Both routes, load-balanced equally
4. D) Neither, until the administrator resolves the conflict
Answer: B — The static route, because a lower administrative distance wins
When the same prefix is learned from different sources, the router prefers the source with the lowest administrative distance; a static route (1) beats OSPF (110). Equal-cost load balancing only happens between routes from the same protocol with equal metrics. (Objective 2.1)
3. A small office has one router with a single default route pointing to the ISP. Which type of routing is this?
1. A) Dynamic routing
2. B) Static routing
3. C) Policy-based routing
4. D) Route redistribution
Answer: B — Static routing
A manually configured default route (0.0.0.0/0 next-hop ISP) is static routing — it does not change unless an administrator changes it. Dynamic routing learns routes from a protocol such as OSPF, policy-based routing forwards on criteria other than destination, and redistribution shares routes between protocols. (Objective 2.1)
4. A switch port connects to another switch and must carry traffic for VLANs 10, 20 and 30 simultaneously. How should the port be configured?
1. A) As an access port in VLAN 10
2. B) As an 802.1Q trunk port
3. C) As a mirrored (SPAN) port
4. D) With port security enabled
Answer: B — As an 802.1Q trunk port
An 802.1Q trunk tags each frame with its VLAN ID so multiple VLANs can share one link between switches. An access port carries a single untagged VLAN, a SPAN port copies traffic to an analyser, and port security limits which MAC addresses may use a port — neither of the last two carries multiple VLANs. (Objective 2.2)
5. After a second uplink is added between two switches, the network slows to a crawl and switch CPUs spike. Which protocol, if enabled, would have prevented this?
1. A) Link Aggregation Control Protocol (LACP)
2. B) Spanning Tree Protocol (STP)
3. C) VLAN Trunking Protocol
4. D) Address Resolution Protocol
Answer: B — Spanning Tree Protocol (STP)
Two parallel links without STP create a Layer 2 loop; broadcasts circulate endlessly in a broadcast storm and the MAC tables flap. STP blocks the redundant path until it is needed. LACP would bundle the two links into one logical link (also loop-free), but the question asks which protocol prevents the loop itself, and STP is the direct answer. (Objective 2.2)
6. A technician wants to combine two 1 Gbps switch uplinks into a single logical 2 Gbps link with failover. Which technology provides this?
1. A) Jumbo frames
2. B) Link aggregation (LACP / 802.3ad)
3. C) Port mirroring
4. D) Native VLAN tagging
Answer: B — Link aggregation (LACP / 802.3ad)
Link aggregation bundles multiple physical links into one logical interface, increasing bandwidth and surviving the loss of a member link; LACP (802.3ad/802.1AX) negotiates the bundle. Jumbo frames raise the MTU, port mirroring copies traffic, and the native VLAN is the untagged VLAN on a trunk. (Objective 2.2)
7. A VoIP phone and a PC share one switch port, with the PC plugged into the phone. Which switch feature powers the phone over the same Ethernet cable?
1. A) Power over Ethernet (802.3af/at)
2. B) Quality of Service
3. C) Voice VLAN
4. D) Auto-MDIX
Answer: A — Power over Ethernet (802.3af/at)
PoE (802.3af, 802.3at PoE+, and 802.3bt for higher power) delivers DC power over the data cable so phones and access points need no separate supply. QoS prioritises voice traffic, a voice VLAN separates phone traffic logically, and Auto-MDIX detects cable type — none of them supply power. (Objective 2.2)
8. Users in a dense office complain of slow Wi-Fi on 2.4 GHz. The three access points are set to channels 1, 3 and 5. What is the BEST change?
1. A) Set all access points to channel 6
2. B) Use the non-overlapping channels 1, 6 and 11
3. C) Increase transmit power on every access point
4. D) Disable 5 GHz so clients stay on 2.4 GHz
Answer: B — Use the non-overlapping channels 1, 6 and 11
2.4 GHz channels are 5 MHz apart but each signal is about 20 MHz wide, so channels 1, 3 and 5 overlap and interfere. Only channels 1, 6 and 11 do not overlap in North America. Putting every AP on one channel maximises interference, more power makes overlap worse, and disabling 5 GHz removes the less-congested band. (Objective 2.3)
9. Which Wi-Fi standard operates in the 6 GHz band in addition to 2.4 GHz and 5 GHz?
1. A) 802.11ac (Wi-Fi 5)
2. B) 802.11n (Wi-Fi 4)
3. C) 802.11ax (Wi-Fi 6E)
4. D) 802.11g
Answer: C — 802.11ax (Wi-Fi 6E)
Wi-Fi 6E is the 802.11ax standard extended into the 6 GHz band, which offers many more non-overlapping channels. 802.11ac is 5 GHz only, 802.11n uses 2.4 and 5 GHz, and 802.11g is 2.4 GHz only. (Objective 2.3)
10. A company needs to connect two buildings 300 metres apart with Wi-Fi where cabling is impossible. Which antenna type is the BEST choice for the link between them?
1. A) Omnidirectional antennas on both ends
2. B) Directional antennas pointed at each other
3. C) A mesh of indoor access points
4. D) A captive portal
Answer: B — Directional antennas pointed at each other
A point-to-point bridge uses directional (for example Yagi or parabolic) antennas that focus the signal toward each other, giving the gain and range a fixed link needs. Omnidirectional antennas spread energy in all directions and waste it, indoor mesh APs are not designed for outdoor spans, and a captive portal is an authentication web page. (Objective 2.3)

Reading answers is not the same as recalling them. When you have worked through every domain, take the timed Network+ N10-009 practice test: it shuffles the questions and options and scores you by domain, so you can see whether this one still needs work.

Network+ N10-009 Domain 2: Network Implementation — 10 practice questions with answers

Objectives in this domain

What to focus on

Practice questions and explanations

1. Two routers from different vendors must exchange routes inside the same organisation. Which routing protocol is an open standard that both are most likely to support?

2. A router has learned the same destination network from OSPF (administrative distance 110) and from a static route (administrative distance 1). Which route is installed in the routing table?

3. A small office has one router with a single default route pointing to the ISP. Which type of routing is this?

4. A switch port connects to another switch and must carry traffic for VLANs 10, 20 and 30 simultaneously. How should the port be configured?

5. After a second uplink is added between two switches, the network slows to a crawl and switch CPUs spike. Which protocol, if enabled, would have prevented this?

6. A technician wants to combine two 1 Gbps switch uplinks into a single logical 2 Gbps link with failover. Which technology provides this?

7. A VoIP phone and a PC share one switch port, with the PC plugged into the phone. Which switch feature powers the phone over the same Ethernet cable?

8. Users in a dense office complain of slow Wi-Fi on 2.4 GHz. The three access points are set to channels 1, 3 and 5. What is the BEST change?

9. Which Wi-Fi standard operates in the 6 GHz band in addition to 2.4 GHz and 5 GHz?

10. A company needs to connect two buildings 300 metres apart with Wi-Fi where cabling is impossible. Which antenna type is the BEST choice for the link between them?