5.5 Given a scenario, use the appropriate tool or protocol to solve networking Issues Flashcards
After plugging a cable into a computer, a user reports there is no network access.
Which of the following tools would the technician MOST likely check to verify that the cable was crimped correctly?
Cable certifier
An employee reports to the IT department that a web application is not loading by its domain name. The issue is resolved after a network administrator updates the DNS records and flushes the DNS resolver cache on the employee’s workstation.
Which of the following commands was likely utilized by the administrator to address the problem?
- Pathping
- ifconfig
- ping
- ipconfig
ipconfig
The ipconfig utility is used to verify the Internet Protocol (IP) configuration on Windows-based systems. Providing the /flushdns argument clears the DNS resolver cache allowing for the proper identification of host names.
The pathping utility performs a trace route, then pings each hop router a given number of times for a given period to determine the Round Trip Time (RTT) for the path.
The ifconfig command is a UNIX/Linux-based utility used to gather or configure information about the Internet Protocol (IP) configuration of a network adapter.
The ping utility can be used to send a configurable number and size of ICMP (Internet Control Message Protocol) packets to a destination host to perform a basic connectivity test.
To determine why the network is running slowly, an administrator wants detailed properties for the cable run, including how much attenuation, crosstalk, noise, and resistance are on it.
What tool should the administrator use to gather all of this information?
- OTDR
- Multimeter
- Cable Tester
- Spectrum Analyzer
Cable Tester
The administrator should use a cable tester that reports detailed information on the cable’s physical and electrical properties, including crosstalk, attenuation, noise, and resistance.
A multimeter’s purpose is to test electrical circuits, but it can test for the continuity of any copper wire if a cable tester is not available.
An optical time-domain reflectometer (OTDR) locates breaks in fiber by sending light pulses down the cable and timing how long it takes for any reflections to bounce back from the break.
An administrator would use a spectrum analyzer with fiber optic cabling, usually with wavelength division multiplexing (WDM), to ensure that each channel has sufficient power.
What is a network command-line utility in MS Windows that tracks and displays the route taken by IPv4 packets on their way to another host known as?
- netstat
- ping
- nslookup
- tracert
tracert
The tracert command is used to show several details about the path that a packet takes from the computer or device to whatever destination is specified.
Ping is the primary TCP/IP command used to troubleshoot connectivity, reachability, and name resolution. This command can be used to test both the computer name and the IP address of the computer.
Nslookup is a network administration command-line tool for querying the Domain Name System (DNS) to map a domain name and IP address or other DNS records.
The netstat command generates displays that show network status and protocol statistics. It can display the status of TCP and UDP endpoints.
An administrator measures the resistance between the two ends of a cable and verifies that the cable has a break.
What tool allows the administrator to test the cable end resistance?
- TAP
- Tone generator
- Multimeter
- Loopback Adapter
Multimeter
The purpose of a multimeter is for testing electrical circuits, but it can test for the continuity of any copper wire by measuring the resistance across the cable.
A network tone generator and probe trace a cable from one end to the other by applying a signal on the cable tracing it to follow the cable over ceilings and through ducts.
A network loopback adapter (or loopback plug) is a specially wired RJ-45 plug with a 6” stub of cable that sends the packet back to itself to test for bad ports and network cards.
A test access point (TAP) reads the signals from the network stack and will either output two streams to monitor a full-duplex link or rebuild the streams into a single channel.
Which of the following is a command-line packet capturing utility?
- tcpdump
- nmap
- zenmap
- netcat
tcpdump
Tcpdump is a packet analyzer that is launched from the command line. It can analyze network traffic by intercepting and displaying packets created or received by the computer it is running on.
Zenmap is a free and open-source GUI for Nmap. It is available on many operating systems and makes Nmap easier to use.
Netcat is a utility tool that uses TCP and UDP connections to read and write in a network. It can be used for both attacking and security.
Nmap can find live hosts on a network, perform port scanning, ping sweeps, OS detection, and version detection.
A workstation’s network board is currently configured as follows:
Network Speed = Auto
Duplexing = Auto
The workstation is experiencing poor network performance, and you suspect that the network board is incorrectly detecting the network speed and duplex settings. Upon investigation, you find that it’s running at 10 Mbps half-duplex. You know that your network switch is capable of much faster throughput. To fix this issue, you decide to manually configure these settings on the workstation.
Before you do so, you need to verify the switch port configuration for the connected workstation.
Given that it’s a Cisco switch, which commands can you use on the switch to show a list of all switch ports and their current settings? (Select two.)
- Show Interface
- Show interface capabilities
- Show running-config interface
- Show interface ethernet counters
Show Interface
Show Running-config Interface
To view the speed and duplex settings of interfaces on a Cisco switch, you can use one of the following commands:
show running-config interface (displays concise summary information)
show interface (displays extended information)
The show interface capabilities command displays information about interface capabilities, not the current switch configuration.
The show interface ethernet counters command displays interface statistics.
The show interface switchport command displays VLAN information regarding switch interfaces.
An administrator is using a wire map tester to identify different types of issues with cabling.
What kinds of issues can the wire map tester detect? (Select all that apply.)
- Incorrect pin-out
- Bad Port
- Short
- Continuity
Incorrect pin-out
Short
Continuity
A wire map tester can detect issues with continuity, or an open, in the cable due to cable damage or because the installer did not properly wire the connector.
A wire map tester can detect issues with a short when two conductors are touching at some point, usually because the insulating wire is damaged or a poorly wired connector.
A wire map tester can detect issues with an incorrect pin-out when the installer incorrectly wired the conductors into the terminals at one or both ends of the cable.
Administrators use loopback adapters to detect bad ports. The loopback plug causes the packet sent by the network interface card to return to itself.
Which of the following commands displays the general NetFlow data on the command line?
- show ip cache flow
- show mls netflow ip
- show iperf
- show ip flow export
show ip cache flow
The show ip cache flow command displays the NetFlow accounting statistics. This would show a visualization of general NetFlow data.
To display the status and the statistics for NetFlow accounting data export, including the main cache and all other enabled caches, use the show ip flow export command in user EXEC or privileged EXEC mode. This shows more advanced accounting statistics than the show ip cache flow command.
Iperf is a network performance utility that can generate TCP and UDP traffic to test bandwidth, latency, and packet loss.
The show mls netflow ip command displays NetFlow IP entries.
Following a cybersecurity incident, IT security analysts discover that unauthorized access was gained through unused protocols enabled on a network device.
Which of the following tools should the analysts employ to identify the exploited vulnerabilities?
- netstat
- dig
- pathping
- arp
netstat
The netstat command allows for checking the state of unused protocols on a local host. Service misconfigurations can be found by using this command.
The Address Resolution Protocol (ARP) arp command is used to perform the task of resolving a logical Internet Protocol (IP) address to a physical hardware address.
The pathping utility performs a trace route, then pings each hop router a given number of times for a given period to determine the Round Trip Time (RTT) for the path.
The domain information groper (dig) utility is used to query a Domain Name System (DNS) server and return information about a particular domain name.
A network manager cannot communicate with a system on the network that has an Internet Protocol (IP) address of 192.150.060.024. The network manager enters the command arp -a 192.150.060.024.
What is the result of entering this command?
- It will add an entry to the Address Resolution Protocol (ARP) table.
- An error result will occur due to an invalid command.
- It will display the Address Resolution Protocol (ARP) cache contents for the IP address.
- It will delete the entry for the IP address in the Address Resolution Protocol (ARP) table
It will display the Address Resolution Protocol (ARP) cache contents for the IP address.
The command arp -a 192.150.060.024 will provide the contents of the Address Resolution Protocol (ARP) cache. The command will only show the contents for this Internet Protocol (IP) address. The command can also be used without an IP address to view the entire table.
The command arp -s 192.150.060.024, when followed by the Media Access Control Address (MAC), would allow the administrator to add an entry to the ARP cache.
The command arp -d 192.150.060.024 would delete the entry for the IP address.
The command arp 192.150.060.024 will not return a result as it is not a valid command.
A systems administrator is unable to ping remote hosts from a Debian server. However, remote hosts can ping the server. The administrator troubleshoots the issue by examining the OUTPUT chain.
Which of the following tools meets the administrator’s needs to troubleshoot the issue?
- iptables
- ipconfig
- ifconfig
- route
iptables
The iptables command line utility is used to edit the rules enforced by the Linux kernel firewall. It can change INPUT, OUTPUT and FORWARD chains that are firewall rulesets.
The route command is a command utility to configure and manage the routing table on a Windows or Linux host.
The ipconfig command is only supported on Windows systems. It is used to display and verify the IP configuration.
The ifconfig command displays a similar output as the ipconfig command. It can display IP information, traffic statistics, and even enable or disable a network adapter.
A Wi-Fi router is unable to reach all users on the office floor due to radio interference.
Which of the following tools have the capability to pinpoint the origin of the interference?
- Protcol Analyzer
- Spectrum Analyzer
- Power Meter
- Tone Generator
Spectrum analyzer
Received signal strength indication (RSSI) signal strength can help identify WiFi signal issues. A spectrum analyzer, usually a handheld device, is used to analyze radio or electrical interferences. The exact location can be pinpointed using this device.
A network tone generator applies a signal on the cable to be traced by a probe, and can be used to follow the cable over ceilings and through ducts.
A power meter or light meter is used to test a fiber optic cable to determine if there is a break in the cable.
A protocol analyzer is a software tool like Wireshark. Working in conjunction with a packet sniffer, it can decode a captured frame to reveal its contents in a readable format.
An organization hires a network technician who discovers that none of the previous technicians had labeled the cabling in the organization’s headquarters building.
What tool can the technician use to locate the ends of each cable for labeling?
- Cable tester
- Multimeter
- Wire map tester
- Network tone generator
Network Tone Generator
A network tone generator and probe trace a cable from one end to the other by applying a signal on the cable tracing it to follow the cable over ceilings and through ducts.
A multimeter’s purpose is to test electrical circuits, but it can test for the continuity of any copper wire if a cable tester is not available.
Wire map testers can test for and identify problems with cable continuity, a short, a split pair, and incorrect pinouts like reversed pair and crossed pair.
A cable tester reports detailed information on the physical and electrical properties of the cable, such as cable conditions, crosstalk, attenuation, noise, resistance, and other characteristics of a cable run.
A cable installer is testing fiber optic cable for spectral attenuation with the goal of ensuring that each channel has enough power to support wavelength division multiplexing.
What tool is the cable installer using?
- ODTR
- OSA
- Tone Generator
- Multimeter
OSA
An administrator would use an optical spectrum analyzer (OSA) with fiber optic cabling, usually with wavelength division multiplexing (WDM), to ensure that each channel has sufficient power.
An optical time domain reflectometer (OTDR) locates breaks in fiber by sending light pulses down the cable and timing how long it takes for any reflections to bounce back.
A tone generator and probe trace a cable from one end to the other by applying a signal on the cable tracing it to follow the cable over ceilings and through ducts.
A multimeter’s purpose is to test electrical circuits, but it can test for the continuity of any copper wire if a cable tester is not available.
An employee’s desktop is not communicating on the network. The network technician verifies that the network interface card is functioning correctly and wants to check the switch port to make sure it is also functioning. The switch is in another room, and no network diagram shows which switch port the technician should check.
What tool can the technician use to find the other end of the cable plugged into the switch?
- Multimeter
- Wire map tester
- Network tone generator
- Cable Tester
Network tone generator
A network tone generator and probe trace a cable from one end to the other by applying a signal on the cable tracing it to follow the cable over ceilings and through ducts.
A multimeter’s purpose is to test electrical circuits, but it can test for the continuity of any copper wire if a cable tester is not available.
Wire map testers can test for and identify problems with cable continuity, a short, a split pair, and incorrect pinouts like reversed pair and crossed pair.
A cable tester reports detailed information on the physical and electrical properties of the cable, such as cable conditions, crosstalk, attenuation, noise, resistance, and other characteristics of a cable run.
An IT specialist deploys a Wi-Fi analyzer application on a tablet to assess the performance of a newly implemented wireless network in a large conference room.
Which of the following does the Wi-Fi analyzer deliver that is crucial for determining the effectiveness of the network layout?
- Channel graph
- Channel bandwidth
- AP List
- Signal strength
Signal-strength
Depending on the position of the tablet, the Wi-Fi analyzer can display how strong the signal is from the location of the access point (AP). This can be used to troubleshoot signal loss in certain areas.
An AP list will show all available wireless access points that the smart phone is able to hear. The Service Set Identifier (SSID) of the AP will be listed.
A channel graph will show the channel the access point is using, along with channels of other APs. This graph can help mitigate channel overlap.
Channel bandwidth is not displayed on a Wi-Fi analyzer app. An online bandwidth speed tester can be used to determine the speed of the wireless network.
Which of the software tools allows you to obtain a domain name to IP address mapping?
-nslookup
-netstat
- tracert
- pathping
nslookup
Nslookup is a network administration command-line tool for querying the Domain Name System (DNS) to map a domain name and IP address or other DNS records.
The tracert command is used to show several details about the path that a packet takes from the computer or device to whatever destination is specified.
Pathping combines the functionality of ping with that of tracert. It is used to locate spots that have network latency and network loss.
The netstat command generates displays that show network status and protocol statistics. It can display the status of TCP and UDP endpoints.
A network manager cannot communicate with a system on the network that has an Internet Protocol (IP) address of 192.150.060.024. The manager uses the ping command and can reach the IP address.
Which of the following commands can the network manager use for troubleshooting this issue?
- arp 192.150.060.024
- arp -a 192.150.060.024
- arp -s 192.150.060.024
- arp -d 192.150.060.024
- arp -a 192.150.060.024
It is possible that two systems on the network have the same Internet Protocol (IP) address and the Address Resolution Protocol (ARP) table has the other system stored in the cache. This can be verified by using the command arp -a 192.150.060.024 and reviewing the returned Media Access Control (MAC) address.
The command arp -s 192.150.060.024 will not assist the network manager. The -s option allows administrators to add an entry to the ARP cache. The administrator would add the MAC behind the IP.
The -d option will delete the entry for the IP address. This will not assist with troubleshooting.
The command arp 192.150.060.024 will not return a result as it is not a valid command.
