Chapter 3 Troubleshooting

Diagnosing Problems

Table 3-1 Common Problems and Solutions (continued)

Problem

Solution

 

 

No connectivity

Verify that the devices at both ends of the link are connected

 

and powered.

 

Verify that the autonegotiation settings are the same at both

 

ends.

 

Verify that you are using the appropriate Ethernet cable for the

 

connected device. See Table 2-1 on page 2-17for cabling

 

requirements.

 

Verify that the cable is good by testing it on another device.

 

Replace it with a known working cable.

 

STP might be checking for possible loops. Wait 30 seconds for

 

the port LED to turn green.

 

For 1000BASE-T connections, make sure to use a twisted

 

four-pair, Category 5 cable.

 

The switch is not recognizing a GBIC module. See the “GBIC

 

Module Slots” section on page 1-6for Cisco-recommended

 

GBIC modules, and see your GBIC module documentation for

 

more information.

 

 

Poor performance or excessive

There might be a speed and duplex autonegotiation mismatch.

errors

Use the show controllers ethernet-controller privileged

 

EXEC command to display per-port send and receive statistics

 

read from the hardware. You can also use the show interfaces

 

privileged EXEC command to display the administrative and

 

operational status of all ports or a specified port.

 

The cabling distance might be exceeded. Reduce the cable

 

length to within the distances listed in the “Front-Panel

 

Description” section on page 1-4.

 

 

Catalyst 3550 Switch Hardware Installation Guide

3-4

OL-6155-01

 

 

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Cisco Systems 3550 manual Use the show controllers ethernet-controller privileged

3550 specifications

Cisco Systems 3550 is a series of enterprise-class multilayer switches that have gained popularity in both enterprise and service provider networks. Introduced in the early 2000s, the 3550 series was designed to meet the increasing demand for advanced networking capabilities, including Layer 2 and Layer 3 switching, making it suitable for various network environments.

A standout feature of the Cisco 3550 is its support for advanced Layer 3 switching capabilities. This means it can perform routing functions similar to traditional routers while maintaining the speed and efficiency of a switch. The 3550 facilitates IP routing, enabling enhanced communication among different subnets without the need for additional routing devices.

The Cisco 3550 series is equipped with a range of ports, typically providing up to 48 Ethernet 10/100 ports and optional Gigabit Ethernet ports, ensuring scalability and flexibility in various network designs. The switches support Power over Ethernet (PoE), allowing the delivery of electrical power through Ethernet cables to connected devices, such as IP phones and wireless access points, streamlining installations and reducing cable management complexity.

Quality of Service (QoS) is another essential feature of the Cisco 3550. The switch supports advanced QoS mechanisms, which provide the ability to prioritize traffic. This is crucial in environments where bandwidth is limited, as it ensures that time-sensitive applications, like VoIP and video conferencing, receive sufficient bandwidth to function optimally.

In terms of security, the Cisco 3550 includes features such as access control lists (ACLs), port security, and VLANs (Virtual Local Area Networks). These features help in segmenting network traffic and preventing unauthorized access to sensitive information, thereby enhancing network security.

The Cisco 3550 is highly regarded for its robustness and reliability, making it a suitable choice for various organizations looking to maintain high availability in their networking environments. Its management capabilities include support for Cisco's IOS software, which offers a command-line interface for configuration, as well as options for SNMP and web-based management tools.

Overall, the Cisco Systems 3550 series is well-regarded for its multilayer switching capabilities, comprehensive feature set, and versatility in meeting the diverse needs of modern networking, making it a favored solution for businesses aiming to build efficient and secure network infrastructures.