How to Make an Ethernet Crossover Cable

When you join two similar devices on a network (whether they are routers, switches, or computers), both devices must be joined using an ethernet crossover cable. Imagine you want to transfer files from one computer directly to another one without going through an existing network. Here you are creating a two node network and you must use a crossover cable to join the computers since the devices are similar. So how do you build one at home?

Materials Required

Standard CAT-5 Cable
RJ-45 Modular Connector
RJ-45 Crimping Tool

Procedure

CAT-5e Networking cable has a standard RJ-45 connector on both ends as shown in Figures 1 and 2. Cut one of the connectors off of one end of the cable and strip the outer sheath approximately 2.5cm (1 inch) from the end (Figure 3).

A Standard CAT-5e Cable
Figure 1 - A Standard CAT-5e Cable with an RJ-45 Connector

A Standard RJ-45 Connector
Figure 2 - A Standard RJ-45 Connector

A Standard CAT-5e Cable
Figure 3 - Strip Approximately 2.5cm of the Outer Sheath

Arrange the eight twisted inner wires to correspond to the pattern in figure 4 below. Make sure to observe the orientation of the connector tab and insert the wires into the modular connector. In the figure below, this assumes looking at the connector TAB UP, CONTACTS FACING LEFT

Wiring Diagram for an Ethernet Crossover Cable
Figure 4 - Wiring Diagram for an Ethernet Crossover Cable

Once you are sure of the correct orientation, crimp the connector contacts onto the eight wires securely using the crimping tool. Once this has been completed, you now have an "all-purpose" ethernet crossover cable!