54CHAPTER 4: PROBLEM SOLVING

Solving Problems

If the LEDs on the Switch indicate a problem, refer to the list of suggested

Indicated by LEDs

solutions below.

The Power LED does not light

Check that the power cable is firmly connected to the Switch and to the supply outlet. If the connection is secure and there is still no power, you may have a faulty power cord or an internal fault. Firstly, check the power cord by:

testing it in another device

connecting a working power cord to the ‘problem’ device

then contact your supplier for advice.

On powering-up, the Power/Self Test LED lights yellow

The Switch unit has failed its Power On Self Test (POST) because of an internal problem. If a port has failed it’s POST, it’s LED will flash green/yellow alternately to indicate that the port is disabled. Contact your supplier for advice.

A link is connected and yet the Status LED for the port does not light

Check that:

The Switch and the device at the other end of the link (or cable) are connected securely.

The devices at both ends of the link are powered-up

The quality of cable is satisfactory

Auto-negotiation settings are the same at both ends.

Auto-negotiation problems will occur with all ports where auto-negotiation is disabled and incorrect cables are being used (cross-over or straight).

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3Com 4228G, 4250T, 4226T manual Solving Problems, Indicated by LEDs, Solutions below, Power LED does not light

4250T, 4226T, 4228G specifications

The 3Com 4228G, 4226T, and 4250T are professional-grade network switches designed for businesses seeking to enhance their network infrastructure. These models offer robust performance and reliability, catering to various networking needs, from small offices to large enterprise environments.

The 3Com 4228G switch is a 28-port gigabit Ethernet switch designed for high-bandwidth applications. It provides 24 Gigabit Ethernet ports with 802.3af Power over Ethernet (PoE) capability, allowing devices such as IP phones and wireless access points to be powered directly through the Ethernet cables. This feature simplifies installation and reduces additional cabling costs. The switch also supports VLAN tagging for network segmentation, improving security and performance. Its advanced traffic management lets IT administrators prioritize network traffic effectively, ensuring critical applications receive the necessary bandwidth.

On the other hand, the 3Com 4226T is a 26-port gigabit Ethernet switch, primarily designed for environments requiring a high level of connectivity without PoE. It offers similar features to the 4228G, such as VLAN support and enhanced traffic management capabilities. The 4226T is ideal for businesses that do not require power over Ethernet yet need reliable, high-speed networking capabilities. With 26 ports, this switch is an excellent choice for medium-sized enterprises looking to upgrade their network infrastructure without overwhelming their existing resources.

The 3Com 4250T is a more advanced switch, offering 48 Gigabit Ethernet ports and a robust feature set suitable for more complex networking environments. It includes Layer 2 and Layer 3 functionality, allowing for advanced routing and switching capabilities, making it highly adaptable to various network designs. The 4250T also simplifies network management through its extensive configuration options and support for IPv6. Moreover, it features an efficient cooling system and reduced power consumption, aligning with today’s growing demand for energy-efficient solutions.

All three models utilize advanced technologies such as Spanning Tree Protocol (STP) for loop prevention, QoS mechanisms to prioritize traffic, and comprehensive security features to protect the network from unauthorized access. With their different port configurations and capabilities, the 3Com 4228G, 4226T, and 4250T switches provide exceptional performance and flexibility, making them ideal for businesses aiming to enhance their networking capabilities.