Mac OS X 10.2: Internet Sharing Does Not Work When MTU Value Is Exceeded

Internet Sharing will not work with certain Internet service providers, because the maximum transmission unit (MTU) value of the ISP is set lower than that of Mac OS X. This document explains how to resolve the issue.
Symptom

The computer that is sharing its connection may connect to the Internet, but client computers (those that are using the shared connection) experience these issues:

Other Internet-related issues may be caused by an MTU issue.


Various Internet service providers could be affected, and some customers of these are known to be affected:

Solution

Update to Mac OS X 10.2.5 or later.

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.
Published Date: Feb 17, 2012