Configuring auto-MDIX

Copper ports on the switch can automatically detect the type of cable configuration (MDI or MDI-X) on a connected device and adjust to operate appropriately.

This means you can use a "straight-through" twisted-pair cable or a "crossover" twisted-pair cable for any of the connections—the port makes the necessary adjustments to accommodate either one for correct operation. The following port types on your switch support the IEEE 802.3ab standard, which includes the "Auto MDI/MDI-X" feature:

  • 10/100-TX xl module ports

  • 100/1000-T xl module ports

  • 10/100/1000-T xl module ports

Using the above ports:

  • If you connect a copper port using a straight-through cable on a switch to a port on another switch or hub that uses MDI-X ports, the switch port automatically operates as an MDI port.

  • If you connect a copper port using a straight-through cable on a switch to a port on an end node—such as a server or PC—that uses MDI ports, the switch port automatically operates as an MDI-X port.

Auto-MDIX was developed for auto-negotiating devices, and was shared with the IEEE for the development of the IEEE 802.3ab standard. Auto-MDIX and the IEEE 802.3ab Auto MDI/MID-X feature are completely compatible. Additionally, Auto-MDIX supports operation in forced speed and duplex modes.

For more information on this subject, see the IEEE 802.3ab standard reference. For more information on MDI-X, the installation and getting started guide for your switch.