OT Tuner 1.0 switches off an option in Open Transport that would cause a Macintosh to respond to certain small network packets with a large Internet Control Message Protocol (ICMP) packet. This update prevents Macintosh computers from being used in certain types of Denial of Service (DoS) attacks.
This update will only function on computers running Open Transport 2.5.x. This includes all computers running Mac OS 9, as well as iBook, Slot-Loading iMac, and most Power Macintosh G4 computers running Mac OS 8.6.
Apple has identified certain issues that may occur after installing the Open Transport Tuner 1.0. These include:
- After installing the Tuner, if you make changes in the TCP/IP control panel, you must restart to use TCP services.
- In some circumstances, internet connections (such as DSL or cable modem) that can be maintained through sleep/wake cycles may not be maintained after installing the Tuner.
To resolve these issues and to take advantage of other improvements, Apple recommends that all Open Transport 2.5.x users update to Open Transport 2.6. This update can be downloaded from the Apple Software Updates web site at
http://www.apple.com/swupdates. For more information on Open Transport 2.6, please see Knowledge Base article 32075: "
Open Transport 2.6: What's New".