beautypg.com

3 virtual lans – Planet Technology WGS3-404 User Manual

Page 247

background image

WGS3 Layer 3 Switch User’s Manual

- 239 -

6.3 Virtual LANs

Switches do not inherently support broadcast domains, which can lead to broadcast storms in large

networks that handle a lot of traffic such as NetBUEI or IPX. In conventional networks with routers,

broadcast traffic is split up into separate domains to confine this traffic to the originating group and

provide a much cleaner network environment. Instead of using physically separate subnets which are

linked by traditionally slow routers, this switch creates segregated broadcast domains based on easily

configurable VLANs, and then links these VLANs as required with wire-speed routing.

An IEEE 802.1Q VLAN is a group of ports that can be located anywhere in the network, but

communicate as though they belong to the same physical segment. VLANs help to simplify network

management by allowing you to move devices to a new VLAN without having to change any physical

connections. VLANs can be easily organized to reflect departmental groups (such as Marketing or R&D),

usage groups (such as e-mail), or multicast groups (used for multimedia applications such as video

conferencing).

VLANs provide greater network efficiency by reducing broadcast traffic, and allow you to make network

changes without having to update IP addresses or IP subnets. VLANs inherently provide a high level of

network security since traffic must pass through a configured Layer 3 link to reach a different VLAN.

This switch supports the following VLAN features:

• Up to 255 VLANs based on the IEEE 802.1Q standard

• Distributed VLAN learning across multiple switches using explicit or implicit tagging and GVRP protocol

• Port overlapping, allowing a port to participate in multiple VLANs (Not supported for multilayer mode.)

• End stations can belong to multiple VLANs

• Passing traffic between VLAN-aware and VLAN-unaware devices

• Priority tagging