Nortel Networks 1000BASE-LX, 1000BASE-SX, 1000ASE-XD Features, Virtual Local Area Networks VLANs

34 Chapter 1 BayStack 420 Switch

Avvertenza: Estrarre il cavo di alimentazione è l'unico sistema per spegnere il dispositivo. Il cavo di alimentazione deve essere sempre collegato in una posizione che permetta l'accesso facile e sicuro in caso di emergenza.

Features

The BayStack 420 Switch provides wire-speed switching that allows high-performance, low-cost connections to full-duplex and half-duplex 10/100/1000 Mb/s Ethernet local area networks (LANs). The BayStack 420 Switch provides the following features.

Virtual Local Area Networks (VLANs)

In a traditional shared-media network, traffic generated by a station is transmitted to all other stations on the local segment. Therefore, for any given station on the shared Ethernet, the local segment is the collision domain because traffic on the segment has the potential to cause an Ethernet collision. The local segment is also the broadcast domain because any broadcast is sent to all stations on the local segment. Although Ethernet switches and bridges divide a network into smaller collision domains, they do not affect the broadcast domain. In simple terms, a virtual local area network provides a mechanism to fine-tune broadcast domains.

Your BayStack 420 Switch allows you to create port-based VLANs:

•IEEE 802.1Q port-based VLANs

A port-based VLAN is a VLAN in which the ports are explicitly configured to be in the VLAN. When you create a port-based VLAN, you assign a Port VLAN Identifier (PVID) and specify which ports belong to the VLAN. The PVID is used to coordinate VLANs across multiple switches.

•Auto PVID

When Auto PVID is active, a port that is assigned to a numbered VLAN has the same number for its PVID. For example, if the VLAN is 2, the PVID is 2.

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