Mac OS X 10.3 and later: "Jumbo" packet size is dimmed

Mac OS X can automatically configure the Ethernet port, and most users choose this option. But some networks require a custom, manual setting. When configuring manually, you may see that the Jumbo setting for Maximum Packet Size (MTU) is not available.



The option is dimmed when your Ethernet device does not work with Jumbo frames. The Apple Ethernet devices that support Jumbo Frames are the Gigabit Ethernet PCI-X card and the built-in Ethernet port on the Xserve G5. The card is optional on Xserve, sold separately by the Apple Store, and may be used in the Power Mac G5. For information on third-party Ethernet devices, see the vendor's website.
Published Date: Oct 8, 2016