CompTIA Network+ Certification N10-009 Practice Questions

Page: 1 / 14
Total 600 questions
Question 1

A network administrator is troubleshooting a connectivity issue between two devices on two different subnets. The administrator verifies that both devices can successfully ping other devices on the same subnet. Which of the following is the most likely cause of the connectivity issue?



Answer : A

When two devices on different subnets are unable to communicate, but can communicate with other devices on their own subnet, the issue is most often related to routing. Devices on different subnets require a default gateway to route traffic between networks.

If the default gateway is incorrectly configured, the device won't know how to reach other subnets.

Faulty cables (Option B) or duplex mismatches (Option C) would likely cause connectivity issues even within the local subnet, which is not the case here.

VLAN mismatches (Option D) are typically issues with switch port configurations and would likely cause total loss of connectivity, including within the same subnet.

So, the most probable and logical cause is an incorrect default gateway.


===========

Question 2

Which of the following OSI model layers manages the exchange of HTTP information?



Answer : D

HTTP is an application-layer protocol, so the OSI layer that manages the exchange of HTTP information is Layer 7 (Application). In the Network+ (N10-009) objectives, the OSI model is used to map common protocols to the layers where they operate. HTTP defines how web clients and servers format and exchange requests and responses (methods like GET/POST, headers, status codes, and message bodies). Those behaviors are part of the application services provided to end-user software such as web browsers, APIs, and web servers.

While HTTP relies on lower layers to function (for example, TCP at the Transport layer for reliable delivery and IP at the Network layer for addressing and routing), the protocol logic and meaning of the web transactions exist at the Application layer. The distractors do not fit: the Network layer handles IP routing, the Data Link layer handles frames and MAC addressing on local links, and the Session layer is associated with session establishment/management concepts but is not where HTTP is categorized for Network+ mapping. Therefore, Application is the correct answer.

===========


Question 3

A network administrator is setting up two new firewalls for redundancy and needs to implement a redundant internet connection. Which of the following routing technologies will the administrator most likely use?



Answer : D

The answer is D. BGP. When a company wants a redundant internet connection, especially across more than one external path or provider, Border Gateway Protocol (BGP) is the routing technology most commonly associated with that design. BGP is used between autonomous systems and is the standard protocol for making routing decisions across the internet or between an organization and one or more ISPs.

The other options are interior routing protocols. EIGRP, RIPv2, and OSPF are generally used inside an organization to exchange routes within a private network environment. They are not the normal answer when the question specifically says internet connection redundancy. That wording points outward, beyond the internal LAN or campus routing domain.

In practical terms, BGP gives administrators a way to influence path selection, advertise network prefixes, and maintain reachability if one outside connection fails. That is why it appears in questions involving multihoming, ISP failover, or resilient edge connectivity. Since the scenario mentions redundant firewalls and a need for a redundant internet connection, the best match is the routing technology designed for external route exchange. For Network+, that technology is BGP.


Question 4

Which of the following involves an attacker traversing from one part of a network to another part that should be inaccessible?



Answer : C

VLAN hopping allows an attacker to send traffic into another VLAN without authorization, often by impersonating a switch and negotiating a trunk link. This lets the attacker traverse into normally inaccessible VLANs.

A . MAC flooding disrupts switch operations but does not cross VLANs.

B . DNS poisoning corrupts name resolution.

D . ARP spoofing reroutes local traffic but doesn't grant VLAN traversal.

Reference (CompTIA Network+ N10-009):

Domain: Network Security --- VLAN attacks, unauthorized lateral movement.


Question 5

A network administrator is reviewing a production web server and observes the following output from the netstat command:

Which of the following actions should the network administrator take to harden the security of the web server?



Answer : A

The netstat output shows that multiple ports are open, including Telnet (23), FTP (20), and TFTP (69), which are potential security risks. Disabling unused ports minimizes the attack surface, reducing security vulnerabilities.

Breakdown of Options:

A . Disable the unused ports -- Correct answer. Unused ports should be closed to prevent unauthorized access.

B . Enforce access control lists -- ACLs help control access but do not disable unnecessary services.

C . Perform content filtering -- Content filtering controls web traffic, not port security.

D . Set up a screened subnet -- A DMZ (screened subnet) improves security but does not address open ports.


CompTIA Network+ (N10-009) Official Study Guide -- Domain 3.4: Given a scenario, implement network security measures.

CIS Benchmark for Linux & Windows Server Hardening

Question 6

A network administrator needs to divide a Class B network into four equal subnets, each with a host range of 1,000 hosts. Which of the following subnet masks should the administrator use?



Answer : B

The best answer is B. 255.255.252.0, which is a /22 mask. A Class B network starts with a default mask of 255.255.0.0 or /16. The question says the administrator wants four equal subnets, which means borrowing 2 bits from the host portion, since 2 borrowed bits gives 2 = 4 subnets. That moves the mask from /16 to /18 if subnetting is based only on splitting the Class B into four equal parts.

However, the answer choices point toward the host requirement as the deciding factor. Each subnet needs to support about 1,000 hosts. A /22 leaves 10 host bits, which gives 2 = 1024 total addresses, or 1022 usable hosts after subtracting the network and broadcast addresses. That fits the requirement. Among the options provided, 255.255.252.0 is the only mask that supports around 1,000 hosts per subnet.

The smaller masks, /24 and /25, do not allow enough hosts. The default Class B mask, /16, does not subnet the network at all. Based on the available choices and the host-capacity requirement, 255.255.252.0 is the correct exam answer.


Question 7

Which of the following services runs on port 636?



Answer : D, D

LDAP over SSL (LDAPS) uses port 636 to provide secure, encrypted authentication for directory services.

Breakdown of Options:

A . SMTP (Simple Mail Transfer Protocol) -- Uses port 25, not 636.

B . Syslog -- Uses port 514 (UDP), not 636.

C . TFTP (Trivial File Transfer Protocol) -- Uses port 69 (UDP), not 636.


CompTIA Network+ (N10-009) Official Study Guide -- Domain 3.1: Compare and contrast network protocols.

RFC 4511: Lightweight Directory Access Protocol (LDAP)

Page:    1 / 14   
Total 600 questions