Intel-based Macs: Compatibility with Gigabit Ethernet switches

Some Gigabit Ethernet switches, using early versions of Broadcom 1000BASE-T PHY (Broadcom 5400), were manufactured and shipped before the IEEE 802.3ab specification was finalized and they do not comply with the final specification. These switches are not compatible with Intel-based Macintosh computers using the 1000BaseT setting.

Intel-based Macintosh computers will detect a link with some non-compliant switches, but can't interoperate with the switches at the 1000BaseT speed setting. You can change the settings on the Intel-based Mac to operate with these switches at the 100BaseTX setting instead.

To change the speed setting:

1. From the Apple menu, select System Preferences...
2. Select the Network pane.
3. Highlight the Built-in Ethernet line and click the Configure... button.
4. Select the Ethernet tab.
5. Change the Configure: drop-down menu to Manually (Advanced).
6. Change the Speed: drop-down menu to 100baseTX.
7. Click the Apply Now button.

Important: Information about products not manufactured by Apple is provided for information purposes only and does not constitute Apple's recommendation or endorsement. Please contact the vendor for additional information.