Ethernet Switching Basics

AT-9000/28 Gigabit Ethernet ecoSwitch Installation Guide

MAC Address Table

An Ethernet switch interconnects network devices, such as workstations, printers, routers, and other Ethernet switches, so that they can communicate with each other by sending and receiving Ethernet frames.

Every hardware device on your network has a unique MAC address. This address is assigned to the device by the device’s manufacturer. For example, when you install a Network Interface Card (NIC) in a computer so that you can connect it to the network, the NIC already has a MAC address assigned to it by its manufacturer.

The MAC address table in the AT-9000/28 Gigabit Ethernet ecoSwitch can store up to 8K MAC addresses. The switch uses the table to store the MAC addresses of the network end nodes connected to the ports, along with the port number on which each address was learned.

A switch learns the MAC addresses of the end nodes by examining the source address of each packet received on a port. It adds the address and port on which the packet was received to the MAC table if the address had not already been entered in the table. The result is a table that contains all the MAC addresses of the devices that are connected to the switch’s ports, and the port number where each address was learned.

When the switch receives a packet, it also examines the destination address and, by referring to its MAC address table, determines the port on which the destination end node is connected. It then forwards the packet to the appropriate port and on to the end node. This increases network bandwidth by limiting each frame to the appropriate port when the intended end node is located, freeing the other switch ports for receiving and transmitting data.

If the switch receives a packet with a destination address that is not in the MAC address table, it floods the packet to all the ports on the switch. If the ports have been grouped into virtual LANs, the switch floods the packet only to those ports which belong to the same VLAN as the port on which the packet was received. This prevents packets from being forwarded into inappropriate LAN segments, decreasing network security. When the destination end node responds, the switch adds its MAC address and port number to the table.

If the switch receives a packet with a destination address that is on the same port on which the packet was received, it discards the packet without forwarding it on to any port. Since both the source end node and the destination end node for the packet are located on the same port on the switch, there is no reason for the switch to forward the packet.

AT-9000/28 specifications

The Allied Telesis AT-9000/28 is a versatile and robust network switch designed for organizations seeking to enhance their networking capability. This Layer 2 managed switch delivers a high degree of performance and reliability, making it an ideal choice for businesses that require a seamless network experience.

One of the main features of the AT-9000/28 is its 28 ports, which include 24 Fast Ethernet ports and 4 Gigabit Ethernet uplink ports. This allows for flexible network configuration and scalability, accommodating both wired and wireless devices efficiently. The switch also supports auto-negotiation and auto-MDI/MDI-X, which simplifies installation and connectivity by automatically detecting and configuring the appropriate settings.

The AT-9000/28 employs advanced switching technologies, such as IEEE 802.1Q VLAN tagging, which enables the segregation of traffic for improved security and performance. This feature is crucial for businesses that require data isolation between different departments or user groups. In addition, the switch supports quality of service (QoS) protocols, allowing for traffic prioritization. This is particularly beneficial for organizations that handle multimedia applications or VoIP services that demand reliable bandwidth.

Another significant characteristic of the AT-9000/28 is its support for port mirroring. This capability is essential for network monitoring and troubleshooting, as it allows administrators to track and analyze network traffic efficiently. Furthermore, the switch supports multiple user authentication methods, including RADIUS and TACACS+, thus enhancing network security.

The AT-9000/28 is built with energy efficiency in mind, featuring Energy Efficient Ethernet (EEE) technology. This reduces power consumption during periods of low traffic without compromising performance, which aids in lowering overall operational costs.

In terms of management, the AT-9000/28 offers versatile management options, including a web-based GUI, Command Line Interface (CLI), and SNMP support. This flexibility enables network administrators to configure, monitor, and troubleshoot the switch easily.

Overall, the Allied Telesis AT-9000/28 is a reliable switch well-suited for a variety of network environments. Its combination of performance, security features, and energy efficiency makes it an excellent choice for organizations looking to optimize their network infrastructure. With robust capabilities and advanced technologies, the AT-9000/28 stands out as a valuable addition to any networking setup.