Cisco CATALYST 3920 24 PORT TOKEN RING SWITCH 规格指南
Physical Characteristics of the Catalyst 3920
Catalyst 3920 Token Ring Switch User Guide
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Physical Characteristics of the Catalyst 3920
The Catalyst 3920 has a CPU planar board with 24 RJ-45 Token Ring ports, one ProStack port, one
connector for a Cisco Redundant Power Supply (RPS) unit, and one RS-232 port for management
and configuration.
connector for a Cisco Redundant Power Supply (RPS) unit, and one RS-232 port for management
and configuration.
Front of the Catalyst 3920
Figure 1-1 shows the front of the Catalyst 3920.
Figure 1-1
Front View of the Catalyst 3920
Status and Activity Indicators
The Catalyst 3920 has LEDs that indicate the status and activity of the base switch and its ports.
There are three LEDs associated with the switch: power (PWR), mode (MODE), and fault (FLT).
There are also three LEDs associated with the stack port: transmit (TX), receive (RX), and
attach (AT). There are two LEDs associated with each of the 24 ports: port status and activity. See
“Hardware Troubleshooting” for more information about the status indicators.
There are three LEDs associated with the switch: power (PWR), mode (MODE), and fault (FLT).
There are also three LEDs associated with the stack port: transmit (TX), receive (RX), and
attach (AT). There are two LEDs associated with each of the 24 ports: port status and activity. See
“Hardware Troubleshooting” for more information about the status indicators.
Reset Button
The Catalyst 3920 has a reset button that is located on the front panel of the switch. Pressing the reset
button resets the hardware and software and clears all tables and memory, including the address
tables. Pressing the reset button does not clear those values stored in NVRAM. This button is
recessed to prevent accidental activation.
button resets the hardware and software and clears all tables and memory, including the address
tables. Pressing the reset button does not clear those values stored in NVRAM. This button is
recessed to prevent accidental activation.
System Request Button
The System Request (SYSREQ) button is on the front panel below the Reset button. This button
causes the System Request Menu to appear on the console attached to the EIA 232 port. The System
Request Menu contains options for downloading new software, resetting the switch, and clearing
NVRAM.
causes the System Request Menu to appear on the console attached to the EIA 232 port. The System
Request Menu contains options for downloading new software, resetting the switch, and clearing
NVRAM.
Caution
If this button is pressed for longer than 5 seconds, a download of the main image will be
forced. This function should be used only at the direction of service personnel. The button is recessed
to prevent accidental activation.
to prevent accidental activation.
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