Chapter 11: Setting Port-based and Tagged VLANs

Overview

Port-based

VLANs

Tagged VLANs

A VLAN is a group of ports that form a logical Ethernet segment on an Ethernet switch. The ports of a VLAN form an independent traffic domain in which the traffic generated by the nodes remains within the VLAN.

VLANs let you segment your network through the switch’s management software so that you can group nodes with related functions into their own separate, logical LAN segments. These VLAN groupings can be based on similar data needs or security requirements. For example, you could create separate VLANs for the different departments in your company, such as one for Sales and another for Accounting. Both port-based and tagged VLANs are supported in the web interface.

A port-based VLAN is a group of ports on a Gigabit Ethernet Switch that form a logical Ethernet segment. Each port of a port-based VLAN can belong to only one VLAN at a time. A port-based VLAN can have as many or as few ports as needed. The VLAN can consist of all the ports on an Ethernet switch, or just a few ports. In addition, a port-based VLAN can span switches and consist of ports from multiple Ethernet switches.

Ports in a port-based VLAN are referred to as untagged ports and the frames received on the ports as untagged frames. The names derive from the fact that the frames received on a port do not contain any information that indicates VLAN membership, and that VLAN membership is determined solely by a port’s PVID.

Port VLAN Identifier

Each port in a port-based VLAN must have a port VLAN identifier (PVID). The switch associates a frame to a port-based VLAN by the PVID assigned to a port on which a frame is received, and forwards a frame only to those ports with the same PVID. Consequently, all ports of a port-based VLAN must have the same PVID. In addition, the PVID of the ports in

a VLAN must match the VLAN’s VID.

For example, if you create a port-based VLAN on the switch and assign it the VID 5, the PVID for each port in the VLAN needs to be assigned the value of 5.

The second type of VLAN is the tagged VLAN. VLAN membership in a tagged VLAN is determined by information within the frames that are received on a port. This differs from a port-based VLAN, where the PVIDs assigned to the ports determine VLAN membership.

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Allied Telesis AT-9000/28SP, AT-9000/52 manual Port-based VLANs Tagged VLANs, Port Vlan Identifier

AT-9000/52, AT-9000/28SP, 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.