Network Troubleshooting and Tools (3) Flashcards
Which of the following troubleshooting tools is not used to test copper cabling installations?
Wiremap tester
Multimeter
OTDR
OTDR
An optical time domain reflectometer (OTDR) is a device that transmits light pulses over a fiber-optic network and measures the time interval and strength of the returning pulse, to measure the length of the cable run. An OTDR can be used to locate fiber-optic cable breaks, as well as characterize a cable run’s reflectance, optical return loss, and other characteristics. Multimeters, tone generators, and wiremap testers are all devices that work only with copper networks
Ralph has been advised to check his Linux web servers for open ports that attackers might be able to use to penetrate the servers’ security. Which of the following utilities can Ralph use to do this?
dig
iptables
nmap
nmap
The nmap utility is capable of scanning a system for open ports that might be a security hazard. The tcpdump, dig, and iptables utilities cannot do this
While performing a protocol analysis, Alice notes that there are many ICMP packets in her captured traffic samples. She attributes these to her frequent use of TCP/IP troubleshooting tools. Which of the following utilities are used to test network layer characteristics of a host using Internet Control Message Protocol (ICMP) messages? (Choose all correct answers.)
ipconfig
netstat
ping
tracert
ping
tracert
ping and tracert are both utilities that test network layer characteristics using ICMP messages. ping tests the network layer functionality of the host, and traceroute displays the path to the host through the internetwork. ipconfig and netstat do not use ICMP messages
Which of the following parameters enables you to specify the time-to-live (TTL) value of the messages ping transmits?
- n
- t
- i
-i
Running the ping tool with the -i parameter enables you to specify the time-to-live (TTL) value of the messages ping transmits. The -t parameter causes the ping tool to send messages to the target continuously until you manually stop it. The -n parameter enables you to specify the number of messages the ping tool should transmit. The -a parameter resolves an IP address you specify as the target to a hostname
Ralph is the network administrator of his company’s network. He has had three users call the help desk to report that they are having problems connecting to the local application server. Comparing their stories, Ralph suspects that their Transmission Control Protocol (TCP) connections are being dropped. The users are not having problems connecting to any other hosts on the network. To troubleshoot this problem, Ralph decides to use a protocol analyzer. He wants to store and view only the traffic relating to the hosts and server that are having problems. How can Ralph do this?
Configure a display filter.
Configure a capture filter.
Set a trap on the analyzer.
Configure a capture filter.
Ralph wants to store and view only the traffic relating to the hosts that are experiencing problems. The best way to do this is to set a capture filter. Capture filters determine what is stored in the buffer. Display filters only determine what is displayed from the contents of the buffer. You do not set a trap on an analyzer—you set traps on Simple Network Management Protocol (SNMP) agents. Also, there is no need to configure both a capture filter and a display filter. If you set a capture filter that blocks all other traffic from entering the buffer, the display filter would be redundant
Ralph is the administrator of his company’s network. All of the users on the network are reporting that they are having difficulty connecting to a particular application server that is located on a perimeter network, on the other side of a router. The users are not having trouble connecting to local hosts. Which of the following troubleshooting tools can Ralph use to verify the network layer functionality of the application server and the router? (Choose all correct answers.)
ping
route
arp
traceroute
ping
traceroute
Ralph can use the ping and traceroute tools to verify the network layer functionality of the application server and the router. The ping tool tests the network layer through the exchange of Internet Control Message Protocol (ICMP) Echo and Echo Reply messages. The traceroute tool can verify that there is a functioning path between the users’ workstations and the application server. The route tool is used to administer the routing table on the local machine. The arp tool is used to view a computer’s Media Access Control (IP to MAC) address resolution table stored in memory
Ralph is a new hire for a consulting firm that frequently performs cable installations. He is trying to learn more about the tools needed to install internal cable runs. To that end, which of the following statements about cable crimpers has Ralph found to be true?
Cable installers use a crimper to attach keystone connectors to lengths of bulk cable.
Cable installers use a crimper to attach RJ45 connectors to lengths of bulk cable.
You need to purchase a separate crimper for each type of cable to which you want to attach connectors.
Cable installers use a crimper to attach RJ45 connectors to lengths of bulk cable.
A crimper is a plier-like device that cable installers use to create patch cables by attaching RJ45 connectors to lengths of bulk cable. Installers do not use a crimper to attach a cable end to a keystone connector. For this, they use a punchdown tool. It is not always necessary to purchase a crimper for each cable type. Although some crimpers are designed for a single cable/connector combination, there are many that have replaceable bits, enabling them to work on a variety of cables and connectors. Making patch cables yourself can represent a false economy. Buying bulk cable and connectors and making patch cables yourself can conceivably be cheaper than purchasing prefabricated cables. However, when you factor in the time needed to attach the connectors, the learning curve required to attach the connectors correctly, and the failure rate requiring the re-application of connectors, it might be more economical to purchase prefabricated patch cables in quantity instead
Which of the following troubleshooting tools enables you to copy all of the packets transmitted over a network to a buffer, interpret the protocols used in the packets, and display the output?
Event Viewer
Traffic monitor
Protocol analyzer
Protocol analyzer
A protocol analyzer copies all network traffic, interprets the protocol headers and fields, and displays the output. The Event Viewer displays system, application, and security event logs on a single computer. There is no network troubleshooting tool called a traffic monitor. A management console is a remote monitoring and management device that queries Simple Network Management Protocol (SNMP) agents
Which of the following are tools that run only on Unix or Linux systems?
iptables
ifconfig
route
route
Of the utilities listed, tcpdump, dig, iptables, and ifconfig are all tools that run on Unix/Linux systems only. The route utility runs on both Unix/Linux and Windows
Which of the following Windows command-line utilities produced the output shown here?
Server: trv213.pljd.net
Address: 203.186.120.114
Non-authoritative answer:
Name: microsoft.com
Addresses: 104.43.195.251
23.100.122.175
23.96.52.53
191.239.213.197
104.40.211.35
nslookup
pathping
netstat
nslookup
nslookup is a command-line utility that generates DNS resource record requests and sends them to a specific DNS server. The output shown here specifies first the name and address of the DNS server to which the request was sent and then the response to the request, containing the name to be resolved and the IP addresses contained in the server’s resource record for that name. The pathping, netstat, and route utilities cannot perform DNS queries
Which of the following parameters enables you to specify the number of messages the ping tool transmits?
- n
- t
- i
-n
Running the ping tool with the -n parameter enables you to specify the number of messages the ping tool should transmit with each execution. The -t parameter causes the ping tool to send messages to the target continuously until you manually stop it. The -i parameter enables you to specify the time-to-live (TTL) value of the messages ping transmits. The -a parameter resolves an IP address you specify as the target to a hostname
Which of the following cable testing tools are used only on fiber-optic networks?
OTDR
Multimeter
Tone generator
OTDR
An optical time domain reflectometer (OTDR) is a device that transmits light pulses over a fiber-optic network and measures the time interval and strength of the returning pulse, to measure the length of the cable run. An OTDR can be used to locate fiber-optic cable breaks, as well as characterize a cable run’s reflectance, optical return loss, and other characteristics. Multimeters, tone generators, and punchdown tools are all devices that work only with copper networks
Which of the following statements about cable certifiers are true? (Choose all correct answers.)
A cable certifier eliminates the need for tools like tone generators and wiremap testers.
Cable certifiers are the most inexpensive cable testing solution.
Cable certifiers must be reconfigured whenever a new cable specification is standardized.
Cable certifiers can only test copper-based cables.
A cable certifier eliminates the need for tools like tone generators and wiremap testers.
Cable certifiers must be reconfigured whenever a new cable specification is standardized.
Cable certifiers can detect all of the faults that tone generators and wiremap testers can detect, and they can do a great deal more, such as specify whether a cable run meets the performance specifications defined in a cable standard. When testing a new cable type, the specifications defined in the cable standard must be added to the device. Cable certifies are far more expensive than most other cable testing solution. Cable certifiers are available that support various cable media, including copper and fiber optic
Alice is the network administrator of her company’s network. The company has just moved into a building that has existing Category 6 (CAT6) unshielded twisted pair cabling. However, none of the cable connections has been labeled, and Alice is trying to identify and document where each cable run starts and ends. Which tools can Alice use for this purpose? (Choose all correct answers.)
A packet sniffer
A loopback connector
A tone generator and locator
A wiremap tester
A tone generator and locator
A wiremap tester
Alice can use a tone generator and locator or a wiremap tester to identify and test cable connections. By connecting the tone generator and or the remote wiremap unit to one end of a cable run, she can use the locator or the master wiremap unit to find the other end. This can enables her to identify a starting point and an ending point for a cable run. A loopback connector is used to test the transmission and reception capabilities of a port. A packet sniffer captures and analyzes network traffic; it cannot identify cables
Ralph is a network administrator who has had a Windows user report difficulties accessing certain other computers on the network. Ralph determines that the user is only experiencing problems when trying to connect to a system on the far side of a router. Ralph therefore decides to inspect the routing table on the user’s computer. Which of the following tools can he use to do this? (Choose all correct answers.)
nbtstat
route
nslookup
netstat
route
netstat
The route print tool displays the contents of the routing table on a Windows computer. So does the netstat -r command. The nbtstat and nslookup tools cannot display the routing table
