The Network Software Installer (NSI) 1.5 contains the Apple Built-In Ethernet driver file version 1.0.1. This driver file contains drivers for all Apple built-in Ethernet implementations and is installed in the extensions folder.
The Macintosh Quadra 660AV and 840AV, Power Macintosh 6100/60, 6100/66, 7100/66, and 8100/80, and Workgroup Server 6150, 8150, and 9150 Ethernet drivers were updated to eliminate slowdowns, hangs, lost connections, and data corruptions that were possible on some Ethernet networks. Installing NSI 1.5 or later fixes this problem.