Practice Free N10-009 Exam Online Questions
A network administrator needs to add 255 useable IP addresses to the network. A /24 is currently in use.
Which of the following prefixes would fulfill this need?
- A . /23
- B . /25
- C . /29
- D . /32
A
Explanation:
A /23 subnet provides 512 total addresses, of which 510 are usable (subtracting 2 for network and broadcast addresses). This would satisfy the need for 255 additional addresses.
Which of the following is the step that a troubleshooter should take immediately after implementing a solution?
- A . Review lessons learned during the process.
- B . Establish a plan of action.
- C . Verify full system functionality.
- D . Document actions and outcomes.
C
Explanation:
After implementing the solution, the immediate next step is to verify full system functionality. This confirms that the problem has been resolved and helps ensure no new issues have been introduced.
From Andrew Ramdayal’s guide:
“After the solution is implemented, test the system to ensure that it is fully operational, and the original problem has been resolved. Also, put in place any measures that could prevent the issue from recurring.”
A company is implementing a new internal network in which all devices use IPv6 addresses.
Which of the following routing protocols will be best for this setup?
- A . EIGRP
- B . OSPFv3
- C . BGP4
- D . iBGP
B
Explanation:
For an internal network using IPv6, the best option listed is OSPFv3, which is the OSPF version designed to support IPv6 routing. In Network+ (N10-009) routing objectives, OSPF is a common interior gateway protocol (IGP) used within an organization (an autonomous system) to exchange routes dynamically and converge efficiently. OSPFv3 maintains the link-state approach of OSPF while adding IPv6 support, making it a strong fit for enterprise internal routing where multiple routers and subnets need dynamic path calculation and fast convergence.
BGP4 and iBGP are associated with BGP, primarily used for inter-domain routing on the internet and between large networks; while BGP can carry IPv6 (via MP-BGP), it is generally not the “best” default choice for a typical internal-only enterprise network unless there is a specific design reason. EIGRP can support IPv6 in some implementations, but Network+ typically emphasizes OSPF/OSPFv3 as the widely adopted, vendor-neutral IGP for IPv6 deployments. Given the options and the “best for this setup” wording, OSPFv3 is the most appropriate answer.
Which of the following is the best example of a networking appliance that connects different network segments and directs allowed traffic between specific segments?
- A . Firewall
- B . IDS
- C . Unmanaged switch
- D . (Not provided)
A
Explanation:
A firewall is the best example of an appliance that can sit between network segments and permit or deny traffic flows based on security policy. In Network+ terms, firewalls enforce segmentation controls by applying rules that match on items such as source/destination IP, ports, protocols, and (with next-generation firewalls) even applications. This makes a firewall a common choice for directing allowed traffic between specific segments (for example, allowing users in a workstation VLAN to reach only certain ports on a server VLAN, while blocking everything else). This function is core to network security architecture and is frequently paired with concepts like network segmentation, ACL-style rule sets, and creating security zones.
An IDS (intrusion detection system) primarily monitors traffic and generates alerts on suspicious activity; it does not typically control or “direct allowed traffic” unless it is specifically an IPS (prevention) with inline blocking. An unmanaged switch operates at Layer 2 and forwards frames within a broadcast domain; it does not provide policy-based filtering between security segments. Therefore, the correct answer is Firewall.
Which of the following is the MOST appropriate solution to extend the network to a building located across the street from the main facility?
- A . Multimode fiber
- B . 802.11ac wireless bridge
- C . Cat 6 copper
- D . Loopback adapter
B
Explanation:
An 802.11ac wireless bridge is the most practical solution to connect two nearby buildings without trenching or laying physical cable. It provides high-speed, point-to-point connectivity using directional antennas.
A network engineer configures the network settings in a new server as follows:
IP address = 192.163.1.15
Subnet mask = 255.255.255.0
Gateway = 192.163.1.255
The server can reach other hosts on the same subnet successfully, but it cannot reach hosts on different subnets.
Which of the following is most likely configured incorrectly?
- A . Subnet mask
- B . Gateway
- C . Default route
- D . IP address
B
Explanation:
The default gateway for a network should be an IP address within the subnet, but not the broadcast address.
In this case:
IP: 192.163.1.15
Subnet Mask: 255.255.255.0
This means the network range is: 192.163.1.0 – 192.163.1.255
A network engineer added more APs to improve wireless coverage. However, users now report that the connectivity disconnects and reconnects repeatedly.
Which of the following is causing the issue?
- A . Throughput capacity
- B . Roaming misconfiguration
- C . Channel overlap
- D . Packet loss
C
Explanation:
Adding more access points can improve coverage, but it also increases the risk of co-channel interference if APs are configured on the same or overlapping channels. Channel overlap causes contention and interference, leading to retries, unstable performance, and symptoms that feel like frequent disconnect/reconnect events―especially in dense deployments. Network+ (N10-009) wireless troubleshooting objectives highlight proper channel planning (non-overlapping channels, appropriate channel width) as critical when increasing AP density. If adjacent APs are competing on the same channel (or overlapping channels in 2.4 GHz), clients may experience poor signal-to-noise ratios and repeated reassociations as they struggle to maintain a stable link.
Roaming misconfiguration can cause sticky clients or poor handoffs, but the classic problem introduced immediately after “adding more APs” is interference from bad channel design. Throughput capacity is about available bandwidth and airtime efficiency; it can make things slow, but it doesn’t inherently cause repeated disconnect/reconnect loops like interference does. Packet loss is a symptom that may occur due to interference, but the root cause in the options that best fits the scenario is channel overlap.
An organization wants to ensure that incoming emails were sent from a trusted source.
Which of the following DNS records is used to verify the source?
- A . TXT
- B . AAAA
- C . CNAME
- D . MX
A
Explanation:
A TXT record can be used to store SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) information, which help verify that an email has been sent from a trusted source.
Which of the following should a company implement in order to share a single IP address among all the employees in the office?
- A . STP
- B . BGP
- C . PAT
- D . VXLAN
C
Explanation:
PAT (Port Address Translation) allows multiple devices on a local network to share a single public IP address when accessing the internet. It translates the private IP addresses to a single public IP with different port numbers for each session.
The document states:
“PAT (Port Address Translation) allows multiple devices on a LAN to share a single public IP address by assigning unique port numbers to each session, enabling internet connectivity for all devices.”
A newly opened retail shop uses a combination of new tablets, PCs, printers, and legacy card readers.
Which of the following wireless encryption types is the most secure and compatible?
- A . WPA3
- B . WPA2
- C . WPA2/WPA3 mixed mode
- D . WPA/WPA2 mixed mode
C
Explanation:
WPA2/WPA3 mixed mode provides compatibility for older devices (that only support WPA2) while allowing newer devices to take advantage of stronger WPA3 encryption. This ensures maximum compatibility and security in a mixed-device environment.