Search

What is Auto-MDIX feature in ethernet switches

The ports of latest network switches have a feature called Auto-MDIX.

Before reading further, I strongly recommend you to read following lessons thoroughly and understand the concepts about copper twisted pair cables, straight-through and cross-over types of twisted pair cables from below links.

Twisted Pair STP and UTP cables, Twisted Pair Cable Categories (CAT)
Straight-Through and Cross-Over cables, Difference between Straight-Through and Cross-Over cables

To understand what is Auto-MDI/MDIX, first we need to know what are MDI/MDIX ports.

The port on a workstation computer (or laptop) is called as MDI (Media Dependent Interface). The ports on network switches are called as MDIX (Media Dependent Interface with Crossover).

RJ45 jacks are attached (crimped) to copper twisted pair cables in such a way that the transmit pair pins on one end of the twisted pair cable is connected to the receive pair pins on the other end and vice versa.

network-cable-with-rj45-jack.jpg

If by mistake, the transmit pins on one side is connected to transmit on the other side, communication will fail. Traditionally, there are two types of twisted pair cable crimping. One is called straight through and the other is called as cross over. As discussed in previous lesson (Straight-Through and Cross-Over cables), the transmission pins on a network switch is opposite to that of a workstation computer (or laptop). To connect a workstation computer to a network switch, we need a straight through crimped twisted pair cable. When two workstation computers or switches are connected back-to-back, we need a crossover crimped twisted pair cable to make transmission pins one side match with the receiving pins on other side.

Auto-MDI/MDIX feature allows a switch port to automatically detect what type of port is connected on other end (MDI port or MDIX port) and swap the transmission and receive pins. Thus, the transmission pins on one side may connect with the receive pins on other side.

You may use either straight-through crimped twisted pair cables or crossover crimped twisted pair cables, if your ethernet network switch ports are equipped with Auto-MDIX feature.

Related Tutorials
Introduction to Computer Networking
Responsibilities of a network engineer
What is a Computer Network?
Why we need computer networks?
Different types devices used to create a computer network
Client Operating Systems and Network Operating Systems (NOS)
Common Network Application Software
Local Area Networks (LAN) and Wide Area Networks (WAN)
Campus Area Networks (CAN) and Metropolitan Area Network (MAN)
Logical Classification of Computer Networks - Peer to Peer Networks and Client/Server Networks
Logical Classification of Computer Networks - Centralized and Distributed Computer Network Models
Internetworks, Internet, Intranet and Extranet
What is a Network Protocol
Difference between Proprietary and Standard Protocols
What are RFCs (Request for Comments)
Organizations which control Internet, Network Protocols and Standards
What is network topology
Difference between physical topology and logical topology
Network Topologies - Bus Topology
Network Topologies - Star Topology
Network Topologies - Mesh, Ring and Hybrid Topologies
Network Topologies - Partial-Mesh Topology
Network Topologies - Full-Mesh Topology
Advantages and disadvantages of full-mesh topology
Network Topologies - Ring Topology
Network Topologies - Dual Ring Topology
Network Topologies - Hybrid Topology
Network Topologies - Tree Topology
Point-to-point Topology and Point-to-multipoint Topology
What are wireless networks? Advantages and disadvantages of wireless networks.
Ad hoc Wireless Topology
Infrastructure Wireless Topology
Wireless Mesh Topology
Network Infrastructure Devices and Icons
Network Infrastructure Devices - What is a Hub?
Network Infrastructure Devices - What are Bridges and Switches?
Network Infrastructure Devices - What is a Router?
Network Infrastructure devices - What is a Firewall
Main office (Head Office) and Branch Office Networks
Site-to-Site Network Topologies - Hub and Spoke Toplogy
Site-to-Site Network Topologies - Partial-Mesh Toplogy
Site-to-Site Network Topologies - Full Mesh Topology
What is NIC (Network Interface Card)
Common Network Cable types
Differences between STP and UTP twisted pair cables
Twisted pair cable bandwidth and frequency range
Different types of shields used in STP (shielded twisted pair cable)
TIA/EIA 568A and TIA/EIA-568B standards
Straight-Through and Cross-Over cables
Difference between Baseband and Broadband
Network Access Methods - CSMA/CD, CSMA/CA and Token Passing
IEEE (Institute of Electrical and Electronics Engineers)
IEEE 802 Standards
IEEE 802.11 Standards
LAN Technologies - Ethernet
Ethernet Media Standards
100Base-TX Ethernet Media Standard
100Base-FX Ethernet Media Standard
4D-PAM5 encoding in Gigabit Ethernet
1000Base-T Ethernet Media Standard
1000Base-SX Ethernet Media Standard
1000Base-LX Ethernet Media Standard
10GBase-T 10 Gigabit Ethernet Media Standard
10GBase-SR 10 Gigabit Optical Fiber Ethernet Media Standard
Meaning of 10/100/1000 Ethernet
Twisted pair Cable categories for 1 Gigbit and 10 Gigabit networks
Broadband over Power Line (IEEE 1901-2010 standard)
What is Power over Ethernet (PoE)
What is PoE (Power over Ethernet) Switch
LAN Technologies - Token Ring
Advantages and disadvantages of Fiber optic cable
Structure of fiber optic cable (FOC)
Single Mode Fiber Optic Cable (SMF fiber cable)
Multimode Fiber Optic Cable (MMF fiber cable)
Different types of fiber optic cables
Fiber optic transceivers
Fiber optic connectors
LAN Technologies - Fibre Distributed Data Interface (FDDI)