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C H A P T E R 6 Intel® NetStructure™ 480T Routing Switch User Guide
Changing Port Speed and Duplex Setting
By default, the switch is configured to use auto-negotiation to
determine port speed and duplex setting for each port. You can
manually configure the duplex setting and the speed of 100/1000
Mbps ports, and you can manually configure the duplex setting on
the GBIC ports
The 480T routing switch fast Ethernet ports can connect to either
100BASE-TX or 1000BASE-T networks. By default, the ports
auto-negotiate port speed. You can also configure each port for a
particular speed (either 100 Mbps or 1000 Mbps).
The GBIC ports are statically set to 1000 Mbps, and their speed
cannot be modified.
To configure port speed and duplex setting, use this command:
configure ports <portlist> auto off {speed [100 |
1000]} duplex [half | full]
Except for the 10/100 management port, only 100 Mbps and 1000
Mbps speeds are currently supported.
To configure the switch to auto-negotiate, use this command:
configure ports <portlist> auto on
Flow control is supported only on GBIC ports. It is enabled or
disabled as part of auto-negotiation. If auto-negotiation is set to off,
flow control is disabled. When auto-negotiation is turned on, flow
control is enabled.
Random Early Detection (RED)
Random Early Detection (RED) selectively drops packets when the
output interface begins to show signs of congestion. By dropping
some packets early rather than waiting until the buffer is full, R ED
avoids dropping large numbers of packets at once. This minimizes
the chance of producing waves of congestion followed by periods
when the link is not fully used. Thus, RED allows the transmission
line to be used fully at all times. RED statistically drops more
packets from large users than small, so traffic sources that generate
the most traffic are more likely to be slowed down than traffic
sources that generate little traffic.