A broken cable might have a(n) ___, where one or more of the wires don't connect from one end of the cable to the other. (pg. 733)

A. short

B. wire map problem

C. open circuit

D. impedance mismatch

C. With an open circuit, the path has been interrupted or "opened" at some point so that current will not flow. The signal lacks continuity.

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Cable continuity problem where one or more of the wires in a cable connect to another wire in the cable. (pg. 733)

A. short

B. wire map problem

C. echo

D. open circuit

A. A short occurs when a current follows an unintended path, bypassing the route it's supposed to take. This unintended path usually takes the form of one wire connecting to another (in a normal cable, no wires connect to others).

You'd think this would be a wire map problem, but that occurs when a wire doesn't connect to the proper location in the jack or plug.

Am echo is a unique type of electrical noise caused when cables of different types connect.

When should you use a cable tester to troubleshoot a network cable? (pg. 733)

A. When you have a host experiencing a very slow connection

B. When you have an intermittent connection problem

C. When you have a dead connection and you suspect a broken cable

D. When you are trying to find the correct cable up in the plenum

C. Cable testers can only show that you have a broken or poorly wired cable, not if the cable is up to proper specification.

To troubleshoot a slow connection, you'll need a certifier to see if a cable isn't moving data like it should.

For an intermittent connection problem, you'll need a time domain reflectometer (TDR) or optical TDR.

To find a specific cable, you'll need a tone probe and tone generator.

You can use a ___ and a ___ to monitor server rooms over time to detect and record issues with electricity and heat. (pg. 736)

A. voltage quality recorder

B. optical power meter

C. time domain reflectometer

D. temperature monitor

A. and D. You can use a voltage quality recorder and temperature monitor to look for problems that might point to heat or power issues; server rooms that get too hot at certain times of the day, switches that fail whenever an air conditioning system kicks on, and so on.

An optical power meter is used to measure the amount of light loss in a fiber optic cable.

A time domain reflectometer is used to check for a break in a cable causing connectivity issues.

Why would you use a tone probe and tone generator? (pg. 737)

A. To locate a particular cable

B. To test the dial tone on a PBX system

C. To run a long-duration ping test

D. To provide safety when working in crawl spaces

A. The tone generator connects to a cable. The tone probe scans the wires and ports on the far end to see which connects.

Which command-line tool would you use to diagnose where the problem lies when you have trouble reaching a remote system? (pg. 739)

A. hostname

B. ipconfig

C. ping

D. tracert/traceroute

D. tracert (traceroute in UNIX/Linux) is used to trace all of the routers between two points. If a traceroute stops at a certain router, you know the problem is either the next router or the connections between them.

The hostname utility does exactly what it says - displays the hostname of the current system.

ipconfig is good for learning just about anything about the system's IP settings, but doesn't help when it comes to making connections to other systems.

ping allows you to the check the "up/down" status of a remote system, but doesn't show you the route it took to get to it.

When would you use the nslookup or dig utility? (pg. 742)

A. To view and change the ARP table on a computer

B. To print out the hostname of the current system

C. To check whether a DNS server is working

D. To check if a remote system is reachable

C. nslookup (all OS) and dig (macOS/UNIX/Linux) help diagnose DNS problems.

The arp utility is appropriately used to modify a computer's ARP table.

To get the hostname of the current system, you can use the literal hostname utility.

You can ping a remote system to see if it's reachable.

Utility to display information on the state of all running IP processes on a system. (pg. 746)

A. ipconfig /all

B. tracert or traceroute

C. netstat

D. packet sniffer

C. The netstat utility shows what IP sessions are active and can also provide statistics based on ports or protocols (TCP, UDP and so on).

The IP config /all utility and switch will give you copious amounts of information on your computer's IP settings, but not active sessions to other devices.

tracert and traceroute will show you the path that a packet travels to get from your device to a destination.

A packet sniffer doesn't focus on a particular device.

What are a couple of ways to troubleshoot a broadcast storm? (pg. 767)

A. Unplug devices until you can find the one causing trouble.

B. Move all of the systems that need to be in a multicast group to their own VLAN or physically separated network.

C. Use a packet analyzer to scoop up a packet to find the bad node.

D. Enable IGMP snooping on your switches.

B. and D. Dealing with a broadcast storm is all about isolating the culprit from the rest of the network.

The other two solutions are for dealing with multicast flooding, which is related to broadcast storms. It's when switches see multicast traffic as broadcasts that they dutifully point forward to every port in the broadcast domain.

How would you define an optical link budget? (pg. 768)

A. The maximum signal loss that a fiber-optic link can have.

B. The max/minimum bandwidth expected from a fiber-optic cable connection to a router.

C. The cost of installation and maintenance of a fiber-optic network.

D. The total distance that a signal on an fiber connection can travel before dropping packets.

A. The optical link budget is the difference between the maximum power a transceiver can transmit and the minimum power it needs to receive a signal.

It's basically how much the signal can attenuate before it runs into trouble.

What is Wireshark? (pg. 746)

A. protocol analyzer

B. packet sniffer

C. packet analyzer

D. All of the above

D. Wireshark can sniff and analyze all the network traffic that enters the computer's NIC.

What will the command route print return on a Windows system? (pg. 744)

A. The results of the last tracert

B. The gateway's router tables
C. The routes taken by a concurrent connection

D. The current system's route tables

D. The route print command returns the local system's routing tables (for IPv4 and IPv6).