A bus contention occurs if Quad Fast-Ethernet (QFE) cards share the same bus with any of the following adapters:
Sun GigaSwift adapter
Sun Dual Gigabit Ethernet and Dual SCSI/P adapter
Sun Quad Gigaswift Ethernet adapter
The infinite-burst parameter of the ce driver that is used by these adapters is enabled by default. Consequently, little or no bus time is available for the QFE ports that share the same bus.
Workaround: Do not place QFE cards on the same bus as the network adapters in the list.