Chapter 2 Overview

Front-Panel Description

Alarm Relay LEDs

Two alarm relay LEDs labeled MAJ and MIN are to the right of the uplink port status LEDs, as shown in Figure 2-7and Figure 2-8. These LEDs reflect the state of the major and minor system alarms.

You can use the Cisco IOS command-line interface (CLI) to configure the major and minor LEDs to drive the relay contacts so that the connected external alarm device state mirrors the alarm state of the major (MAJ) or minor (MIN) LED. You can also use the CLI to associate port and global status alarms to one or both relays. See the switch software configuration guide for details.

Warning The switch relays are rated at 1 Amp and have a voltage limit of 30 VDC and 0.3 Amp at a voltage limit of 125 VAC. It is dangerous to exceed these limitations in a hazardous environment.

An electrical arc can occur when you connect or disconnect the relay wires with field side power applied. This could cause an explosion in switch installations in a hazardous location. Before proceeding, be sure that power is removed or the area is not hazardous. Statement 1061.

Table 2-6lists the LED colors and meanings.

Table 2-6

Alarm and Relay LEDs

 

 

 

 

LED

 

Color

Meaning

 

 

 

 

Major relay

 

Off

Environmental temperature is within normal range, or connected

(MAJ)

 

 

alarm is not in a state of fault.

 

 

 

 

 

 

Red

Environmental temperature exceeds maximum threshold, or

 

 

 

connected alarm is in a state of fault.

 

 

 

 

Minor relay

 

Off

Connected alarm is not in a state of fault.

(MIN)

 

 

 

 

Red

Connected alarm is in a state of fault.

 

 

 

 

 

 

Note The minor LED is disabled by default.

 

Catalyst 2955 Hardware Installation Guide

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Cisco Systems Catalyst 2955 manual Alarm Relay LEDs, Color Meaning

Catalyst 2955 specifications

The Cisco Systems Catalyst 2955 is a robust and versatile Ethernet switch designed for enterprises seeking reliable Layer 2 switching capabilities. Known for its steadfast performance and extensive feature set, the Catalyst 2955 is particularly favored for environments requiring high-density connectivity and advanced traffic management.

One of the hallmark features of the Catalyst 2955 is its support for IEEE 802.1Q VLAN tagging, which allows for efficient traffic segregation and helps improve network security. The switch can handle up to 256 virtual LANs, supporting a more organized network structure and optimized resource allocation. This VLAN capability is crucial for businesses that need to segment their networks for various departments or applications while maintaining efficient communication between them.

The Catalyst 2955 is equipped with a comprehensive Quality of Service (QoS) mechanism, which prioritizes critical applications and ensures that voice, video, and data traffic receive appropriate bandwidth. By providing features such as classification, marking, queuing, and congestion avoidance, the switch helps meet the demands of real-time applications, thereby enhancing user experience and productivity.

Another remarkable technology integrated into the Catalyst 2955 is Spanning Tree Protocol (STP), which prevents loops in redundant network connections. Enhanced with features like Rapid Spanning Tree Protocol (RSTP), this switch minimizes downtime by allowing for quicker convergence times in case of topology changes. The ability to support both STP and RSTP is vital for maintaining network stability and performance.

The Catalyst 2955 is also designed with network management and monitoring in mind. It includes features like Simple Network Management Protocol (SNMP), which enables administrators to manage network resources effectively and troubleshoot issues more efficiently. With support for Cisco’s proprietary software, it offers insights into traffic patterns and usage statistics that can aid in maintaining optimal network health.

Physical characteristics of the Catalyst 2955 include various configurations with either 24 or 48 ports, suitable for different deployment scenarios. The switch is designed for rack mounting, making it an ideal solution for data centers and enterprise networks where space is a consideration.

In summary, the Cisco Systems Catalyst 2955 stands out for its solid Layer 2 functionality, VLAN support, QoS capabilities, network stability features such as STP, and extensive management tools, making it an excellent choice for organizations aiming to enhance network resiliency and performance. Its balance of performance and manageability continues to make it a viable option in the competitive landscape of networking equipment.