Day 12 Quiz - Network Troubleshooting

Objective 5.1/Day 12 -

After gathering information and questioning users about reported connectivity issues, a network technician notices that several users in the same department are experiencing intermittent network outages. The technician suspects a possible issue with the network switch servicing that department. What step in the network troubleshooting methodology should the technician perform next?

• Establish a theory of probable cause

• Implement the solution or escalate as necessary

• Verify full system functionality

• Document findings, actions, outcomes, and lessons learned

Answer explanation

At this stage, the technician has gathered sufficient information to suspect a potential cause (the network switch). The next logical step is to establish a theory to confirm or rule out this suspicion. After establishing the theory, the technician can then proceed to test the theory to determine if the network switch is indeed the source of the problem.

Objective 5.1/Day 12 -

Following the identification of symptoms indicating slow internet connectivity across the entire organization, a network technician decides to perform a speed test to confirm the issue. The speed test reveals significantly lower than expected download and upload speeds. What should the technician do next based on the network troubleshooting methodology?

• Establish a theory of probable cause

• Document findings, actions, outcomes, and lessons learned

• Test the theory to determine the cause

• Establish a plan of action to resolve the problem and identify potential effects

Answer explanation

The technician has confirmed the problem with the speed test results. Now, they need to establish a theory of what might be causing the slow internet connectivity before moving on to testing the theory and planning an action to resolve it.

Objective 5.1/Day 12 -

While troubleshooting a network issue, a technician determines that a misconfigured firewall rule is likely causing the problem. However, upon further investigation, the technician realizes that implementing the correct firewall rule might impact other network services. What step should the technician take next according to the network troubleshooting methodology?

• Gather additional information from affected users

• Reestablish a new theory or escalate

• Document findings, actions, outcomes, and lessons learned

• Implement the solution or escalate as necessary

Answer explanation

Since implementing the correct firewall rule could affect other services, the technician should reassess the situation and consider the potential impact. This may involve revising their theory or consulting with others (escalating) to find a solution that resolves the issue without negatively impacting other services.

Objective 5.3/Day 12 -

Match the following software tools to their purpose:

• Bandwidth speed tester

• Identifying open ports and services running on a remote host, useful for network reconnaissance and security assessments.

• Port scanner

• Analyzing and optimizing wireless network performance by monitoring signal strength, channel usage, and interference sources.

• WiFi analyzer

• Capturing and analyzing network traffic to diagnose network issues, troubleshoot problems, and monitor network performance.

• Protocol analyzer/packet capture

• Assessing network performance by measuring the throughput and bandwidth capacity between two endpoints.

• Iperf

• Testing the speed and quality of an internet connection by measuring the data transfer rate between the client and server.

Answer explanation

WiFi analyzer = Analyzing and optimizing wireless network performance by monitoring signal strength, channel usage, and interference sources.

Protocol analyzer/packet capture = Capturing and analyzing network traffic to diagnose network issues, troubleshoot problems, and monitor network performance.

Bandwidth speed tester = Testing the speed and quality of an internet connection by measuring the data transfer rate between the client and server.

Port scanner = Identifying open ports and services running on a remote host, useful for network reconnaissance and security assessments.

Iperf = Assessing network performance by measuring the throughput and bandwidth capacity between two endpoints.

Objective 5.3/Day 12 -

Match the following software tools to their purpose:

• Terminal emulator

• Facilitating file transfers between network devices, particularly useful for network booting and firmware upgrades.

• TFTP Server

• Scanning a range of IP addresses to discover active hosts on a network, useful for network inventory, security audits, and troubleshooting.

• IP scanner

• Analyzing network traffic flows to monitor bandwidth usage, detect anomalies, and identify trends for network optimization and security.

• NetFlow analyzers

• Providing access to the command-line interface of network devices for configuration, management, and troubleshooting.

Answer explanation

NetFlow analyzers = Analyzing network traffic flows to monitor bandwidth usage, detect anomalies, and identify trends for network optimization and security.

Trivial File Transfer Protocol (TFTP) server = Facilitating file transfers between network devices, particularly useful for network booting and firmware upgrades.

Terminal emulator = Providing access to the command-line interface of network devices for configuration, management, and troubleshooting.

IP scanner = Scanning a range of IP addresses to discover active hosts on a network, useful for network inventory, security audits, and troubleshooting.

Objective 5.3/Day 12 -

A network administrator suspects that a particular network device is experiencing intermittent connectivity issues. Which network software tool would be most appropriate to diagnose and analyze the problem?

• Bandwidth speed tester

• Protocol analyzer/packet capture

• Port scanner

• IP scanner

Answer explanation

A protocol analyzer, also known as a packet capture tool, allows the network administrator to capture and analyze the network traffic to and from the device. This can help identify patterns, errors, or anomalies in the traffic that could be causing the intermittent connectivity issues.

Objective 5.3/Day 12 -

A company wants to assess the performance of its newly deployed wireless network in a busy office environment. They need a tool that can provide detailed information about signal strength, channel interference, and neighboring networks. Which software tool should they use?

• WiFi analyzer

• Trivial File Transfer Protocol (TFTP) server

• NetFlow analyzers

• Terminal emulator

Answer explanation

A WiFi analyzer tool is designed to provide comprehensive insights into the wireless network's performance, including signal strength, channel usage, interference, and the presence of neighboring networks. This information is crucial for optimizing the wireless network's performance and resolving any issues.

Objective 5.3/Day 12 -

A network administrator needs to determine the available IP addresses on a subnet and identify active hosts. Which network software tool would be the most suitable choice for this task?

• iperf

• Port scanner

• Protocol analyzer/packet capture

• Terminal emulator

Answer explanation

A port scanner can scan a range of IP addresses to identify active hosts and open ports. This tool helps network administrators see which IP addresses are in use and which ones are available, as well as gain insights into the services running on those hosts.

Objective 5.3/Day 12 -

Fill in the blank with the command-line tool to match their purpose:

​ (a)   = Tests connectivity between two devices by sending ICMP echo request packets.

​ (b)   = Displays network configuration information, including IP address, subnet mask, and default gateway.

​ (c)   = Resolves domain names to IP addresses and vice versa.

​ (d)   = Displays the route that packets take from the source to the destination, showing each hop along the way.

• ping
• ipconfig/ifconfig/ip
• nslookup/dig
• traceroute/tracert
• netstat
• arp
• route

Answer explanation

ping = Tests connectivity between two devices by sending ICMP echo request packets.

ipconfig/ifconfig/ip = Displays network configuration information, including IP address, subnet mask, and default gateway.

nslookup/dig = Resolves domain names to IP addresses and vice versa.

traceroute/tracert = Displays the route that packets take from the source to the destination, showing each hop along the way.

Objective 5.3/Day 12 -

Fill in the blank with the command-line tool to match their purpose:

​ (a)   = Displays the mapping table that correlates IP addresses to MAC address.

​ (b)   = Provides information about active network connections, routing tables, and network interface statistics.

​ ​ (c)   = Displays or sets the hostname of the system.

​ (d)   = Shows or modifies the IP routing table

• arp
• netstat
• hostname
• route
• ping
• ifconfig
• nslookup

Answer explanation

arp = Displays the mapping table that correlates IP addresses to MAC address.

netstat = Provides information about active network connections, routing tables, and network interface statistics.

hostname = Displays or sets the hostname of the system.

route = Shows or modifies the IP routing table.