8.12 Troubleshooting the Network
8.12.6
The purpose and function of common network tools including: a crossover cable, hardware loopback, tone generator, tone locator (fox and hound)
Crossover Cable

A crossover cable has the appearance of a twisted-pair cable. However, this cable is used to connect two computers together, instead of a computer onto the network. It has a different pin-out than a straight-through patch cable. Crossover cables can also be used to connect two hubs or two switches together.

Loopback

Loopback is a method used to verify if a device, such as a NIC, is working properly. Either an external loopback adapter or an internal device is attached to the NIC. Data
is sent from the NIC out and looped back in to verify if the data received is the same as the data transmitted.

Tone Generator and Tone Locator

Tone generators and tone locators are small handheld devices used to identify wire pairs. Tone generators, also called fox and hound, are used to perform tests on phone and network lines by clipping into the wire, terminal panel, or standard modular jack. By using the fox and hound method, wires can be identified and traced.

A tone generator is placed at one end of the twisted pair to identify a cable. An amplifier is placed on the other end, in the vicinity of the wire, to receive and amplify the audible signal. Using this technique you can identify the wire of interest from among the many wires present.