Ethernet Switching Basics

AT-FS750/24POE Fast Ethernet Smart Switch Installation Guide

MAC Address Table

Duplex Mode

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-FS750/24POE Fast Ethernet Smart switch 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.

Duplex mode refers to how an end node receives and transmits data. If an

AT-FS750/24POE specifications

Allied Telesis is renowned for its high-quality networking solutions, and the AT-FS750 series exemplifies this commitment with its robust functionality and advanced features. The AT-FS750/24POE and AT-FS750/48 are two powerful models designed to meet the diverse needs of modern networks, providing reliable connectivity and efficient power management.

The AT-FS750/24POE model is particularly notable for its Power over Ethernet (PoE) capabilities, allowing it to deliver power and data over the same Ethernet cable. This is especially beneficial for deploying devices like IP phones, security cameras, and wireless access points in locations where power sources may be limited. With 24 PoE-enabled ports, the switch can efficiently power multiple devices simultaneously, streamlining installations and reducing clutter.

Conversely, the AT-FS750/48 offers a more extensive configuration with 48 standard Ethernet ports. This model is ideal for larger networks that require seamless connectivity for a higher number of devices. Its robust architecture ensures optimal performance and reliability in demanding environments, making it a preferred choice for enterprises looking to enhance their infrastructure.

A key feature of both models is the Layer 2 switching technology, which ensures high-speed data forwarding and efficient traffic management within the local area network (LAN). This technology supports essential protocols such as VLAN (Virtual Local Area Network) tagging, enabling network segmentation and better security. The switches also boast a high switching capacity, ensuring minimal latency and maximizing throughput for connected devices.

Both AT-FS750 switches are designed with user-friendly management options. They support a web-based interface, simplifying configuration and monitoring tasks for IT staff. Additionally, the switches incorporate SNMP (Simple Network Management Protocol) for streamlined network management, allowing administrators to oversee network performance and troubleshoot issues effectively.

Another notable characteristic is their compact, fanless design, which not only reduces noise but also extends the lifespan of the equipment due to minimized thermal stress. The rugged casing ensures durability, making them suitable for various environments, from small offices to large enterprise networks.

In summary, the Allied Telesis AT-FS750/24POE and AT-FS750/48 switches provide a versatile solution for organizations seeking reliable and efficient networking capabilities. With PoE support, comprehensive management features, and robust performance, these switches are well-suited to meet the evolving demands of today's networking landscape.