when you are connecting same devices like computer to computer or switch to switch or router to router to use cross over cable.
when you are connecting different devices like computer to switch or computer to router to use straight cable.
Crossover
straight throught
The "Crossover" port. (or MDI-X)
Same device----> crossover cable Different device->Straight through cable
straight through is same pin out both ends. crossover has transmit and receive lines reversed
straight through is same pin out both ends. crossover has transmit and receive lines reversed
straight through is same pin out both ends. crossover has transmit and receive lines reversed
When connecting two computers, use cross-over. Cross-over is required to connect the transmit and receive terminals of the two endpoints. When connecting through a router, switch or hub, use straight-through. The router, switch or hub provides the crossover.
The "uplink" port. If it doesn't have one, you will have to use a crossover cable.
Straight through ethernet cable (CAT 5/5e/6)
There are some great YouTube videos demonstrating the techniques... check them out.
To connect two devices of the same type together. e.g. You would use a crossover cable to connect a router to another router, a switch to another switch or a computer to another computer. If you are connecting diferent devices together, such as a router to a switch, a straight through cable should be used.