Uplink Port

• The uplink port on a router, network switch or hub is an Ethernet port that is separate from the standard ports used to connect computers and other devices to the network. The uplink port is wired differently than standard Ethernet ports with the wiring of some of its connections reversed. This altered wiring makes the uplink port essential when trying to connect multiple switches, hubs or other network devices that would otherwise encounter errors when trying to send data to each other.
  
  

Connecting Hubs

• An uplink port is used to connect two hubs or other network devices by ensuring that no network interference is caused by the connecting of two similar or identical devices. An Ethernet cable is plugged into the uplink port of one hub or device and into a standard Ethernet port on the other device. Data can flow through the ports unobstructed without encountering errors caused by device ports on both ends of the cable having the same transmit and receive settings; the uplink port reverses these settings on one end of the cable so that data can flow freely.
  
  

Dual Mode Devices

• Some network devices feature a switch that allows users to use a port as a standard Ethernet port or an uplink port. If an uplink port isn't necessary in a small network, the user can move the switch so that the uplink port functions as a standard Ethernet port. If an additional hub or other network device is later needed for the network, the port can be switched back to an uplink port at any time.
  
  

Network Troubleshooting

• When errors occur in a network, improper use of an uplink port may be the cause. Any connected devices should be checked to make sure that they are wired correctly with the uplink port on one device connecting to a standard port on another. If the device used for the uplink has a dual-mode switch, the switch should be checked to ensure that it is in the proper position. On some devices, the uplink port is paired side-by-side with a standard Ethernet port; an Ethernet cable in both of these ports can cause problems with some devices, so the cable in the Ethernet port should be moved to a different port to eliminate this problem.