CompTIA A+ Core Certification: A Simple Guide To Networking - Using Networking Tools

220-1101: Objective 2.8: Given a scenario, use networking tools.
Specialized networking tools are needed to build network infrastructure. They can also help in running, terminating, and testing cable. For this short section, imagine that you are the network installer and are required to install a wired network for 12 computers.

To start, check with your local municipality to see if any rules and regulations govern running networking cable. Some municipalities require a person to have an electrician’s license to run networking cable, but most require only an exemption of some sort that anyone can apply for at the town or county seat. Because of the low-voltage nature of network wiring (for most applications), some municipalities have no rules about running it. In urban areas, however, you need to apply for a permit beforehand and then, when you have finished the installation, have at least one inspection done.

Every good network starts with a plan. A diagram of the network, called a topology, acts as a map for computer placement. In this scenario, the diagram will have 12 wired connections to computers (known as drops), depicting where the cables will be run and where they will terminate. All cables will come out of a wiring closet and will be terminated in a small patch panel. On the other end, they will terminate at in-wall RJ-45 jacks near each of the computers. The next sections discuss each of the tools used to complete this job.

When working with computers and computer network equipment, standard household tools are not adequate for the job. A specialized network technician’s toolkit is necessary for quality work. A quick Internet search for “networking toolkit” will return a full range of options in many price ranges. Networking toolkits are also available from nearly every retailer that sells computers and accessories.

Cutting Tool
A good, sharp cutting tool is essential. You need to make a clean cut on the end of the network cable; scissors will not do. Instead, you need either cut pliers or other cable-cutting tools. Klein Tools (www.kleintools.com) is an excellent manufacturer of these types of tools.

Cable Stripper
A cable stripper is used to strip a portion of the plastic jacket off the cable to expose the individual wires. When the wires are exposed, you can separate them and get ready to terminate them.

Figure below illustrates a typical cable stripper.



 

A Cable (Wire) Stripper
 

Crimper
A crimper attaches a connector to the end of raw twisted pair (TP) or coaxial cable. Two types of crimpers are available. If you are working with TP, you need an RJ-45 crimping tool (which often also works with RJ-11 telephone cable). After untwisting the wire pairs and aligning them according to the appropriate standard (typically T568B), insert them into an RJ-45 connector and push the cable and connector assembly into the crimper.

Line up the crimper jaw with the recessed area of the connector and squeeze (see Figure).



Crimping an Ethernet Cable

If you are working with coaxial cable using F type connectors, a compression-crimping tool is recommended. It produces a better, more water-resistant connection than a hex-type crimper.

Punchdown Tool
A punchdown tool (see Figure) punches the individual wires down into the 110 IDC clips of an RJ-45 jack and the patch panel. This “punching down” of the wires is the actual termination. The patch cables connect the various ports of the patch panel to a switch and connect the RJ-45 jacks to the computers.



A Typical Punchdown Tool

Multimeter
A multimeter is a flexible tool that tests both coaxial and TP cabling, as well as AC and DC voltage. (However, testing cables is easier with specially made cable testers.) When set for DC voltage, a multimeter can test computer power supplies and AC adapters. When set for continuity (CONT), it can be used as a cable tester. It can also test ohm (resistance) and ampere (amp, or current) levels.
All multimeters are equipped with red and black test leads. When used for voltage tests, the red lead is attached to the power source to be measured and the black lead is attached to ground.
Multimeters use two different readout styles: digital and analog. Digital multimeters are more common today because their costs have dropped.

Figure shows a typical digital multimeter.



Typical Digital Multimeter
 

Toner Probe
A toner probe kit consists of two parts:
Tone device: This device connects to one end of the network cable. When it is turned on, it sends a tone along the length of the cable.
Probing device: This device, also known as an inductive amplifier, can pick up the tone anywhere along the cable length and at the termination point.
A toner probe is not as handy as a proper network cable tester because it tests only one pair of the wires. However, it is an excellent tool for finding individual phone lines and is commonly used for that.

Cable Tester
A necessary item for a PC technician’s toolkit is a proper network cable tester. This device includes a LAN testing unit that you plug into a port on the patch panel and a terminator that you use to plug the other end of the cable into the corresponding RJ-45 jack. This tool tests each wire in the cable and makes sure everything is wired properly.
Some cable testers, such as the one shown in Figure below, can also be used to test coaxial cable using F connectors, BNC connectors, or RCA connectors.



A Typical Cable Tester Equipped for Testing RJ-45 and Coaxial Cable
 

Loopback Plug
A loopback plug connects directly to the RJ-45 port of a PC’s network adapter. When you use a loopback plug with a network diagnostic program, it simulates a network and tests whether the network adapter and TCP/IP are functioning properly.

Wi-Fi Analyzer
A Wi-Fi analyzer provides an easy-to-use view of both 2.4GHz and 5GHz wireless networks in the area. A Wi-Fi analyzer can be a standalone device, a program for a desktop computer, or an app on a smartphone.
An example is the Intel Killer Control Center Wi-Fi analyzer program for Windows.

Figures below show the 2.4GHz and 5GHz wireless networks in an office building. Wi-Fi analyzers are helpful when determining what channel is best to use, as well as what channels are currently being used by other wireless access points.



Using the Intel Killer Control Center Wi-Fi Analyzer to View the 2.4GHz Wireless Network in an Office


Using the Intel Killer Control Center Wi-Fi Analyzer to View the 5GHz Wireless Network in an Office

You can also use smartphone apps such as Wi-Fi Analyzer (from olgor.com, available on Google Play), the built-in Wireless Diagnostics feature in macOS, and the iwlist command in Linux to learn about the channels used by wireless networks in the vicinity.

Network Tap
A network tap allows network managers to “tap” into the data flowing through a network. A tap is a device that is inserted into the network cable and then makes an exact duplicate of network traffic. While the network traffic is sent on to its destination, the copy of traffic is sent to be stored or analyzed for security purposes. The tapped data allows the network to be analyzed without using software inside the network that could slow performance for users. A network tap also can be used for nefarious reasons by spies or hackers.