Ethernet Cable Troubleshooting for Network Connectivity Issues

Common Causes of Failed Desktop Network Connections

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Question

A network technician has salvaged several Ethernet cables from a datacenter.

The technician attempts to use the cables to connect desktops to the network without success.

Which of the following is MOST likely the issue?

A.

The cables have an incorrect pin-out. B.

The cables are UTP instead of STP. C.

The cables are Cat 6 instead of Cat 5. D.

The cables are not plenum rated.

A.

Explanations

A network technician has salvaged several Ethernet cables from a datacenter.

The technician attempts to use the cables to connect desktops to the network without success.

Which of the following is MOST likely the issue?

A.

The cables have an incorrect pin-out.

B.

The cables are UTP instead of STP.

C.

The cables are Cat 6 instead of Cat 5.

D.

The cables are not plenum rated.

A.

The most likely issue in this scenario is that the cables have an incorrect pin-out. Ethernet cables have four pairs of wires that are twisted together, and each pair is assigned a specific function (e.g., transmitting data or receiving data). The pin-out refers to the order in which these wires are terminated on each end of the cable.

If the pin-out is incorrect, the devices on either end of the cable will not be able to communicate with each other, as they will be expecting to receive data on a different wire than the one that is transmitting it. This can result in a variety of connectivity issues, including slow data transfer speeds, dropped connections, and an inability to connect to the network at all.

UTP and STP refer to the type of shielding used in the cable. UTP (Unshielded Twisted Pair) cables are the most common type of Ethernet cable and are used for most standard network connections. STP (Shielded Twisted Pair) cables have an additional layer of shielding that helps to reduce electromagnetic interference, but they are not typically necessary for most network setups.

Cat 5, Cat 6, and other "categories" of cable refer to the specifications and performance capabilities of the cable, such as maximum data transfer speed and distance. Using a higher category of cable than is necessary for a particular network setup will not necessarily cause connectivity issues, but it may be a waste of resources and money.

Plenum-rated cables are designed for use in air handling spaces, such as the ducts and vents in a building's heating and cooling system. These cables are made of materials that are less likely to produce toxic fumes or smoke in the event of a fire, but their use is not necessary for most network setups.

Therefore, in this scenario, the most likely issue is an incorrect pin-out on the Ethernet cables. The technician should check the termination of each wire on both ends of the cable and ensure that they match the appropriate standard for the devices they are connecting.