CompTIA Certifications

CompTIA Network+ 2009 Domain 5: Network Tools

Network Hardware Tools

Network administrators augment their software tools with a variety of hardware tools for testing, create physical network connections, and for monitoring the network environment. For the CompTIA Network+ exam, you must be able to identify the right tool to use at the right time and for the right purpose. In this section, we will review each tool, what it does, and in many cases, what it looks like. You will not need to be an expert in the usage of each tool, but you should be aware of what the tool is and how it can best be used.

Cable Tester

A cable tester is used to test cabling to ensure the actual cable works fine. A cable tester is an electronic device used to verify all of the intended connections exist and that unintended connections do not exist. This will help you ensure a problem is not with a cable wiring.

As you can see on the example cable tester on the right, you connect both ends of a cable on the unit and it will tell you if there are any twisted pairs inside the cable that are miswired, shorted, or otherwise a problem.

Typically, there are two ways to test a connection:

  1. A continuity test. Current is passed down a connection and if it provides a current, it’s assumed the connection is good.
  2. A resistance test. A known current is passed down a connection and the voltage that develops is measured.

For the CompTIA Network+ exam, you should be aware of what a cable tester is and that it can be used to test whether or not a cable is bad. You can use the cable tester to test long cables as well. For example, you can test the cabling from a cable panel to an office jack a 100 feet away.

Protocol Analyzer

A protocol analyzer is a hardware based network analyzer which intercepts and analyzes network traffic on an Ethernet netw0rk.

The protocol analyzer records each packet and analyzes it that travels over a certain network. A protocol analyzer can monitor a lot of data traversing a network from any computer on the network, but many network switches contain a monitoring port which mirrors traffic flowing over the network so it can be logged and analyzed at a single point.

The protocol analyzer connects into a network and allows you to analyze the network traffic.


A multimeter, also known as a volt meter, is an electronic measuring device that combines several measurement functions into a unit. A typical multimeter may include features such as the ability to measure voltage, current, and resistance. A multimeter can be either analog or digital. An analog multimeter uses a microammeter whose pointer moves over a scale calibration for all the different measurements that could be made. A digital multimeter displays digits or a bar.

In a computer network, a multimeter is used in a variety of electrical troubleshooting situations. Commonly, multimeters measure:

  • Voltage, alternating or direct, in volts.
  • Current, alternating or direct, in amperes.
  • Resistance in ohms.

Some multimeters also measure:

  • Capacitance in farads.
  • Conductance in siemens.
  • Decibels.
  • Duty cycle as a percentage.
  • Frequency in hertz.
  • Inductance in henrys.
  • Temperature in Celsius or Fahrenheit.