N10-009 Exam Dumps - CompTIA Network+ Certification Exam

When an organization moves its DNS servers to new IP addresses, the NS (Name Server) records must be updated. The NS record defines which DNS servers are authoritative for a domain. Ifthese records still point to the old IP addresses, clients will continue to query the outdated servers, leading to connectivity issues.

Breakdown of Options:

A. AAAA – This record maps a domain name to an IPv6 address. Since the issue is with DNS resolution, not IP versioning, this is incorrect.

B. CNAME – A CNAME (Canonical Name) record is used for domain aliasing, not for defining authoritative name servers.

C. MX – Mail Exchange (MX) records direct email traffic to the correct mail server, which does not impact general website accessibility.

D. NS – Correct answer. NS records must be updated to reflect the new authoritative DNS servers.

A large number of collisions and input errors typically indicates a duplex mismatch, such as when one device is set to full duplex and the other to half duplex. This leads to communication issues and poor performance. The document explains:

“Collisions and input errors are clear signs of duplex mismatches… typically caused when one device operates in half duplex while the other is in full duplex, causing performance and connectivity issues.”

A cable tester is a tool that can help identify issues with the physical cabling, such as breaks or improper terminations, which may prevent the access point from reaching the internet.

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Comprehensive and Detailed Explanation (aligned to N10-009):

An ad hoc wireless network allows devices to connect directly to each other without an access point. This is suitable for small, temporary setups like two laptops and a printer.

A. Mesh requires multiple nodes forming a larger distributed network.

B. Infrastructure requires an AP, which is not available here.

D. Point-to-point is typically for long-distance wireless links between two fixed endpoints.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Wireless network types: infrastructure, ad hoc, mesh.

Changing the default password is a fundamental step in device hardening, as default credentials are widely known and published online, posing a significant security risk if not updated. The document notes:

“Default passwords are often known by attackers and published on the internet. Changing them to unique, strong passwords is a critical first step in securing network devices against unauthorized access.”

The best answer is SNMP (Simple Network Management Protocol). SNMP enables monitoring of network devices (routers, switches, firewalls, servers) and provides performance data such as CPU usage, bandwidth utilization, and interface status. In this scenario, if SNMP monitoring had been in place, administrators would have received alerts that the router was overutilized before customers noticed outages.

A. Packet capture (e.g., Wireshark) is useful for deep troubleshooting but is reactive, not proactive, and not scalable for continuous monitoring.

C. Syslog collects log messages but generally does not provide proactive resource utilization metrics. It is complementary but not the best fit for this problem.

D. SIEM aggregates logs and security events for analysis, but the primary requirement here is performance and availability monitoring.

By implementing SNMP monitoring (and potentially integrating it with a network monitoring tool such as Nagios, PRTG, or SolarWinds), the organization can track utilization trends, set thresholds, and automatically generate alerts, thereby preventing downtime from going unnoticed.

References (CompTIA Network+ N10-009):

Domain: Network Operations — SNMP monitoring, proactive network performance management.

If APs are changing channels frequently, it indicates automatic channel selection due to interference. This can cause temporary disconnections as the APs switch frequencies.

Breakdown of Options:

A. Channel interference – ✅ Correct answer. APs change channels automatically to avoid interference, causing disconnections.

B. Roaming misconfiguration – Roaming only affects moving users, but users report issues while stationary.

C. Network congestion – Causes slow speeds, not frequent disconnects.

D. Insufficient wireless coverage – Would cause weak signals, but not channel switching issues.

A CNAME (Canonical Name) record maps an alias to the correct fully qualified domain name (FQDN). If a user is redirected to the wrong hostname, correcting or updating the CNAME ensures the alias points to the proper domain.

B. PTR record maps IP to hostname (reverse DNS), not forward website resolution.

C. NTP relates to time sync, irrelevant to DNS resolution.

D. TXT record stores metadata like SPF or DKIM info, not used for hostname aliasing.

References (CompTIA Network+ N10-009):

Domain: Network Standards, Protocols, and Implementations — DNS record types (A, AAAA, CNAME, PTR, TXT).