Switch Description

This chapter describes the Catalyst 4912G hardware features and components and contains the following sections:

Note The Catalyst 4912G switch software is based on the Catalyst 5000 series switch software. Software features, descriptions, examples, and the procedures for implementing them are in the Software Configuration Guide and the Command Reference publication for the Catalyst 4000 series and Catalyst 5000 series switches. There are, however, some configuration differences between the switches. These differences are noted in "Software Configuration for the Catalyst 4912G."

Hardware System Features

The Catalyst 4912G switch is a high-performance dedicated Ethernet switch that fully integrates into the Catalyst family of switches using Catalyst 4000 and 5000 series system software.

The following is an overview of the Catalyst 4912G hardware features:

12 1000BaseT Gigabit Ethernet ports using modular Gigabit Interface Converter (GBIC) interfaces. GBIC ports can be independently configured with the following modules:

1000BaseSX - Shortwave (850 nm) multimode fiber

1000BaseLX/LH - Longwave (1300 nm) single-mode fiber
Console management port
10BaseT management port
An optional, redundant, external power supply

Switch Components

This section describes the Catalyst 4912G hardware components.

Console Port

A console serial port (RJ-45) provides for switch management using standard console equipment (see Figure 2-1). A connector pinout table is provided in "Specifications," for the console and 10BaseT management ports.

10BaseT Port

A 10BaseT port (RJ-45) provides for switch management (see Figure 2-1). Transmission Control Protocol (TCP)/IP-based management services (Telnet, Simple Network Management Protocol [SNMP], File Transfer Protocol [FTP]) are available through this 10BaseT port. IP address configuration via BOOTP and image download are supported on this port.

Note The 10BaseT port is for network management only. This port is not a switching port. There is no connectivity between this port and the 10/100BaseT switching ports.

Figure 2-1: Detailed View of the LEDs and the Management Ports

Reset Button

A Reset button on the front panel of the Catalyst 4912G switch allows you to manually reset the switch. The Reset button is located at the lower left hand side of the front panel (see Figure 2-2). The Reset button is recessed and can be activated by using a pointed object.

Figure 2-2: Detailed View of the LEDs and the Reset Button

Front Panel LEDs

The LEDs on the front panel of the Catalyst 4912G switch (see Figure 2-1 and Figure 2-2) provide status information as follows:

STATUS LEDs indicate the operating state of the Catalyst 4912G switch
Link status LEDs provide 10BaseT management and switching port status
- Each Gigabit Ethernet port and corresponding link status LED is numbered
  from 1 to 12
- A link status LED is below the 10BaseT management port
Utilization LEDs provide an indication of switch activity
PS1 LED indicates the internal power supply status
RPSU LED provides the External Redundant Power Supply Unit status

A description of the LED functions is provided in Table 2-1.

LED	Color or State	Description
STATUS	Green Red Orange Off	The Catalyst 4912G performs a series of diagnostic tests: All tests pass A test other than an individual port test fails System boot or diagnostic tests in progress Switch is disabled
Port	Green Orange Flashing orange Off	Port is operational Port is disabled by user Power-on self-test indicates faulty port No signal detected or link configuration failure
Utilization	Off-0% utilization All On-100% utilization	LEDs light up as the percentage of switch utilization increases
PS1 and RPSU	Green Red	Operational Failure

Table 2-1: LED Descriptions

LED Color or State Description

STATUS

Green
Red
Orange
Off

The Catalyst 4912G performs a series of diagnostic tests:
All tests pass
A test other than an individual port test fails
System boot or diagnostic tests in progress
Switch is disabled

Port

Green
Orange
Flashing orange
Off

Port is operational
Port is disabled by user
Power-on self-test indicates faulty port
No signal detected or link configuration failure

Utilization

Off-0% utilization
All On-100% utilization

LEDs light up as the percentage of switch utilization increases

PS1 and RPSU

Green
Red

Operational
Failure

Chassis Cooling

Note For environmental specifications, see "Site Planning."

The system fan assembly provides cooling air for the internal chassis components. The fans exhaust air from the rear and fresh air is drawn in from the front of the chassis.

Figure 2-3 shows the direction of airflow in and out of the switch.

Figure 2-3: Catalyst 4912G Airflow

If an individual fan fails, the other fan(s) continue to run. Sensors monitor the internal air temperatures. If the air temperature exceeds a desired threshold, the environmental monitor displays warning messages.

Power Sup plies

Note For complete power specifications for the Catalyst 4912G, see Appendix A, "Specifications."

The Catalyst 4912G has an internal power supply and supports a second, external Redundant Power Supply Unit (RPSU). To order an RPSU for a Catalyst 4912G, consult the Cisco Product Catalog.

The internal and optional external power supply have individual power cords and status LEDs (PS1 and RPSU). A power cord is used to connect the power supplies to the site power source. There is no power switch on the Catalyst 4912G switch; AC power is present in the internal power supply when the power cord is plugged in.

The RPSU can be configured to provide redundant power supply protection. The RPSU contains redundant power supplies. If one RPSU power supply fails, the other RPSU power supply can automatically provide power to the Catalyst 4912G switch. For more information and configuration details, see the RPSU user's guide.

Note When you are using the RPSU, only one power source can supply power to the switch. If you are using the RPSU, unplug the local power cord for the switch. If you are using the local power supply, you can connect, but you must not power on the RPSU.

Environmental Monitoring of the Power Supplies

Using the environmental monitoring and reporting functions, you can maintain normal system operation by resolving adverse environmental conditions prior to loss of operation.

Each power supply monitors its own temperature and output voltages. If conditions reach critical thresholds, the power supply might shut down to avoid damage from excessive heat or electrical current. The Catalyst 4912G senses the operating condition of the power supply and reports status through software.

Table of Contents

Switch Description