Apple Computer has released Open Transport 2.6 which addresses DHCP problems experienced by some Mac OS 9 users and prevents Macintosh computers from potentially being used as traffic amplifiers in certain types of denial-of-service attacks. Open Transport 2.6 replaces OT Tuner 1.0, which Apple released last week as a stop-gap measure. (See "OT Tuner 1.0 Combats Possible Net Abuse of Macs" in TidBITS 511 for details on the potential vulnerability.) Open Transport 2.6 is a 1.1 MB download, and only runs on Macintoshes running Mac OS 9, or on Power Macintosh G4s, iBooks, and slot-loading iMacs (like the iMac DVs) running Mac OS 8.6. Open Transport 2.6 is also available via Mac OS 9’s Software Update control panel, so if you have your Macintosh configured to automatically install software updates from Apple, you may get Open Transport 2.6 automatically.