Suppose you were going for a 26+ hours flight, and suppose you had limited luggage allowance...what would you do with your fantastic (but nonetheless heavy...) crimping tool? But who cares!
You just need a physical loopback adapter :D
Here I'll show you how to make one without using a crimping tool:
- Buy a short standard cat.5e ethernet patch cable.
- Cut one of its ends (scissors, knife or strip it badly by rubbing it on the edge of a walkway).
- Once you have your short piece of cable, you need to remove the plastic from the pairs protecting the copper: this can be done with your teeth (!).
- Connect the pairs between them, such as to close the circuit, basically, as you'd do while connecting the pairs of a crossover cable to the other end.
Here's the right scheme:
OrangeWhite joined to GreenWhite.
Orange joined to Green.
Blue joined to BrownWhite.
BlueWhite joined to Brown.
Once your pairs are joined, isolate them one-another (i.e.: with some scotch or duct tape).
Well done! Now you have a new physical gigabit loopback adapter like the one shown in the picture!