University of Oregon

Connecting Two Macs via Ethernet


Connecting two Macs with an Ethernet cable is fairly simple. This page guides those new to the process through some potential challenges.

Basic Connection

For almost any new Mac computer it is very easy to connect two systems via Ethernet cable and possibly an ethernet adapter (although Firewire or Thunderbolt may be a much faster method for sharing files). The following method was tested and work effectively between a Late 2008 and Mid 2009 Macbook Pro 13 inch models but should theoretically work effectively on all computers dating from that point on. It did not require a specific type Ethernet cable, just the wired connection and knowledge of each computers name, account username, and/or the user password of the computer to which one is trying to connect.

1.     Connect both computers with the Ethernet cable. Make sure this is a stable connection. 

2.     On each computer, go to the System Preferences then Sharing and select which items the computer can share with others. Select all relevant items for the process you would like to complete be it basic screen sharing, sharing a DVD or Super Drive, file sharing, or another option. You can also find the name of the computer on this page.

3.     On one of the computers start from the desktop and select Go in the task bar, then Connect to Server, then select Browse.

4.     Double click on the name of the computer you want to connect to (there may only be one option, the other wired computer). This may prompt for a username and password. If connecting fails, double check the Sharing preferences and try selecting Connect As on the failed window. This will force a username and password to be entered. (I had the connection failed issue I believe as both Macbooks had the the same username. Different usernames may prompt for log in information immediately)

5.     To disconnect, first quit screen sharing and all other operations using the shared connection then unplug the Ethernet Cable.

This process is fairly simple. In OSX 10.9 Mavericks it appears that some functions of the settings or system preferences sections mentioned below are no longer available or enabled by default. None of the operations below were tested when the above process was shown to work as the above functionality has replaced the below set up.

The following may be useful for Macs running OSX 10.4 or Earlier.

Determine Your Cable Needs

Depending on the computers you want to connect, you will need one of two types of Ethernet cable: a Straight-Through Ethernet Cable or a Crossover Ethernet Cable.

Most newer Macintosh computers (built after 2000) can use either type of cable automatically. This is done through the use of Auto-Medium Dependent Interface Crossover (Auto-MDIX), a technology that automatically determines the cable type and configures the relevant connection. This means if you have a new Mac and you are connecting to a new Mac you can skip the rest of this tutorial. Use the list before to see if your Mac employs Auto-MDIX. To read more about sharing flies between Macs click here.  

Macs that do not require a crossover cable:

  • iMac (17-inch 1GHz) and later
  • eMac (ATI Graphics) and later
  • iBook (Dual USB) and later
  • Power Mac G4 (Gigabit Ethernet) and later
  • Mac mini
  • Xserve and later
  • Power Mac G5 and later
  • PowerBook G4 and later
  • AirPort Base Station (Dual Ethernet)
  • AirPort Extreme Base Station
  • AirPort Express

Older Macintosh computers only work with the Medium Dependent Interface (MDI) and therefore require the use of an Ethernet Crossover Cable.

This means if you are connecting a newer Mac to an older Mac, or two older Macs to each other, you will need a crossover cable. Once you have determined the needed cable connect the two machines with the cable. 

Macs that require a crossover cable:

  • Power Macintosh G3 (Blue and White)
  • Power Mac G4 (PCI Graphics)
  • Power Mac G4 (AGP Graphics)
  • Power Mac G4 Cube
  • iMac
  • iMac (Slot Loading)
  • iMac (Summer 2000) (See Note)
  • iMac (Early 2001)
  • iMac (Summer 2001) (See Note)
  • iMac (Flat Panel)
  • iMac (17-inch Flat Panel)
  • eMac
  • PowerBook G3 Series (Bronze Keyboard)
  • PowerBook (FireWire)
  • iBook
  • iBook (FireWire)
  • AirPort Base Station (Graphite)

Software Configuration

In the Network preferences panel, select Show Network Port Configurations and make sure Built-in Ethernet is checked. Do this on both machines. Whether Ethernet is active will also be indicated in the Network Status pane of the Network System Preferences panel.

  1. Open the Sharing preferences panel on at least one of the machines and activate Personal File Sharing. You should also note and possibly write down the computer address beginning with "afp" that appears at the bottom of the window on the target machine.
  2. On the other computer, there are two connection methods that may be employed. The first is accessed as a from a Finder window in OS 10.3 or later. Click the network icon in the sidebar.
  3. It may take several seconds for all of the items from your network to appear. Look for one representing the target machine at the opposite end of your Ethernet cable, and click on it.
  4. A dialog will appear asking you to enter your password.
  5. Another dialog will appear showing the available volumes, from you which you can select any or all. Make your selection(s) and click OK. Within a few seconds icons for all of the selected volumes should appear in the sidebar, and you can proceed as if they were hard drive partitions.

Another Method

The advantage of this method is that the icons of volumes on the target computer will show up on your Desktop.

Select "Connect to Server" from the Go menu.

  1. A dialog will appear with a list of favorite servers. If the IP address of your target machine does not appear in the list, click Browse, or alternatively type the IP address of the target machine into the Server Address field.
  2. Click Connect.
  3. A password authentication dialog will appear, and then a dialog showing volume selections on the target machine. Once the icons appear on your Desktop you can treat them as you would any mounted volume.

That's really all there is to setting up a simple two-Mac, Ethernet network.

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