- (Topic 2)
A network technician is investigating an IP phone that does not register in the VoIP system Although it received an IP address, it did not receive the necessary DHCP options The information that is needed for the registration is distributes by the OHCP scope All other IP phones are working properly. Which of the following does the technician need to verify?
Correct Answer:
A
A VLAN mismatch is the most likely reason why an IP phone does not receive the necessary DHCP options for registration. A VLAN mismatch occurs when a device is connected to a switch port that belongs to a different VLAN than the device’s intended VLAN. This can cause communication problems or prevent access to network resources. For example, if an IP phone is connected to a switch port that belongs to the data VLAN instead of the voice VLAN, it may not receive the DHCP options that contain information such as the TFTP server address, the NTP server address, or the default gateway address for the voice VLAN. These DHCP options are essential for the IP phone to register with the VoIP system and function properly. References: https://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified- communications-manager-callmanager/13979-dhcp-option-150-00.html
- (Topic 3)
Users ate moving back into an office that had been vacant for awhile. Ten workstations are hooked up in the office, but one workstation cannot obtain a link with (he switch. A network engineer checks the documentation and cable labeling, and everything is hooked up as expected. The engineer moves the connection lo a different switchport. but a link still cannot be obtained. When the engineer puts a tone generator on (he infrastructure cable, no tone is heard at the far end. Which of the following issues is the engineer MOST likely trying to find?
Correct Answer:
B
A break in the cable means that there is no electrical continuity between the two ends of the cable, which prevents the signal from reaching the switch. A tone generator is a device that sends an audible signal through the cable, and if no tone is heard at the far end, it indicates a break in the cable.
- (Topic 3)
A company streams video to multiple devices across a campus. When this happens, several users report a degradation of network performance. Which of the following would MOST likely address this issue?
Correct Answer:
A
- (Topic 3)
Which of the following demarcation connections would be MOST appropriate to use with a cable modem being installed in a SOHO situation?
Correct Answer:
A
RG6 is a type of coaxial cable that is commonly used for cable TV and internet services. A cable modem is a device that modulates and demodulates signals over a coaxial cable network to provide broadband internet access. A SOHO situation refers to a small office/home office environment that typically has a single cable modem connected to a single coaxial cable outlet. Therefore, RG6 is the most appropriate demarcation connection for a cable modem in a SOHO situation. References: [CompTIA Network+ Certification Exam Objectives], What Is RG6 Cable? | Techwalla
- (Topic 3)
A company has been added to an unapproved list because of spam. The network administrator confirmed that a workstation was infected by malware. Which of the following processes did the administrator use to identify the root cause?
Correct Answer:
A
One possible process that the administrator used to identify the root cause of the spam issue is traffic analysis. Traffic analysis is a technique that monitors and analyzes the network traffic that flows between devices or applications. Traffic analysis can help troubleshoot network problems by identifying the source, destination, volume, frequency, and content of the network packets12.
To use traffic analysis to identify the root cause of the spam issue, the administrator could follow these steps:
✑ Install a traffic analysis tool on the server or a device that is connected to the same
network as the server, such as Wireshark3, tcpdump4, or Microsoft Network Monitor5.
✑ Start capturing the network traffic and filter it by using the IP address or hostname
of the server, or by using a specific port or protocol that is used by the email service, such as SMTP (port 25), POP3 (port 110), or IMAP (port 143).
✑ Analyze the filtered traffic and look for any signs of abnormal or malicious activity, such as high volume of outgoing emails, unknown recipients, suspicious attachments, or spam keywords.
✑ Trace back the source of the spam emails to the infected workstation by using its IP address or MAC address.
✑ Isolate and clean up the infected workstation by using an antivirus or malware removal tool.
The other options are not processes that the administrator used to identify the root cause of the spam issue. Availability monitoring is a technique that measures and reports the uptime and downtime of a network device or service. Availability monitoring can help troubleshoot network problems by detecting any failures or outages that affect the network performance. Baseline metrics are a set of standard measurements that establish the normal behavior or performance of a network device or service. Baseline metrics can help troubleshoot network problems by comparing the current state of the network with the expected state and identifying any deviations or anomalies. Network discovery is a technique that scans and maps the network devices and services that are connected to a network. Network discovery can help troubleshoot network problems by providing a comprehensive and updated view of the network topology and configuration.