Sun Microsystems Sun Quad - Manual (Page 31)

Chapter 3 Configuring the Driver Software 17
Auto-Negotiation
A key feature of the Sun Quad FastEthernet PCI adapter is auto-negotiation. The
auto-negotiation protocol, as specified by the 100BASE-T standard, selects the
operation mode (half-duplex or full-duplex), and the auto-sensing protocol selects
the speed (10 Mbps or 100 Mbps) for the adapter.
The link speed and modes supported by the Sun Quad FastEthernet PCI adapter are
listed as follows in decreasing order of priority:
■ 100 Mbps, full-duplex
■ 100 Mbps, half-duplex
■ 10 Mbps, full-duplex
■ 10 Mbps, half-duplex
When the system is booted, the Sun Quad FastEthernet PCI adapter advertises these
capabilities to the Link Partner at the other end of the link (a hub, switch, or another
network interface card (NIC) in a host system). If the Link Partner also supports
auto-negotiation, it will advertise its capabilities over the link. The common highest
priority mode supported by both sides will be selected automatically for the link
operation.
The qfe device driver operates the SUNW,qfe devices by default in half-duplex
mode only. If the Sun Quad FastEthernet PCI adapter is connected to a remote
system or interface that is not capable of auto-negotiation, your system
automatically selects the speed and half-duplex mode.
If the Sun Quad FastEthernet PCI adapter is connected to a link partner with which
the auto-negotiation protocol fails to operate successfully, you can configure the
device to not use this protocol and force the driver to set up the link in the mode and
speed of your choice.