Product Overview

This chapter provides an overview of the Catalyst 4908G-L3, an eight-port fixed-configuration, multiprotocol Gigabit Ethernet switch router. The switch router components are described in the following sections:

Figure 1-1 shows the front panel of the Catalyst 4908G-L3 switch router.

Figure 1-1: Catalyst 4908G-L3 Switch Router

Gigabit Ethernet Ports

The switch router has eight 802.3z Gigabit Ethernet ports that support the following modular Gigabit Interface Converters (GBICs):

1000BaseSX (short wavelength)
1000BaseLX/LH (long wavelength/long haul)
1000BaseZX (extended distance)

Management Ports

The switch router has two management ports: a console port and an auxiliary port.

A console serial port provides local system management using standard console equipment. (See Figure 1-2.) See Table B-1 for a list of console port pinouts.

The auxiliary port supports remote console interfaces using a modem. (See Figure 1-2.) This port is for network management only and is not a switching port. There is no connectivity between this port and the Gigabit Ethernet ports. See Table B-2 for a list of auxiliary port pinouts.

Figure 1-2: Catalyst 4908G-L3 Console Port and Auxiliary Port

Fan Assembly

The switch router's 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 left, right, and front of the chassis. (See Figure 1-3.)

Figure 1-3: Catalyst 4908G-L3 Internal Airflow

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

Power Sup plies

The switch router has an internal power supply and supports a second, external redundant power supply (RPS). To order a Cisco RPS, refer to the Cisco Product Catalog.

The internal power supply and the Cisco RPS each have individual power cords and status LEDs (PS1 and RPS). The switch router and the Cisco RPS use power cords to connect to the site power source. There is no power on switch on the switch router; AC power is present in the supply when the power cord is plugged in. See Table A-1 for complete power specifications for the switch router.

The Cisco RPS has two power cords and two power switches. When operating from the Cisco RPS, both power switches on the Cisco RPS must be on for power supply redundancy. Refer to the Cisco Hardware Installation Guide for more information about the Cisco RPS.

Caution Use only the y-cable to connect the switch to the Cisco RPS. The y-cable ensures use of the load sharing capabilities of the Cisco RPS.

Note The Cisco RPS output is enabled if the internal power supply fails. The transition causes a power cycle and an automatic system reset.

Note When using the internal power supply, the Cisco RPS is connected and turned on; however, it remains idle unless it is needed.

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 switch router senses the operating condition of the power supply and reports status through the LEDs.

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

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