Intel Express 510T, User Manual

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681872.bok : 68187204 56 Mon Apr 20 15:35:05 1998
Advanced Configuration
VLANs (Virtual LANs)
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VLANs (Virtual LANs)
Purpose
The use of VLANs lets you:
■
Create up to 128 separate user groups
■
Limit broadcast and multicast traffic
■
Increase security by limiting communication between groups
■
Allocate network resources (such as servers) to groups
For a more comprehensive explanation of the VLAN concept, refer
to the online help.
Warning when using STP
It is important to be aware of problems that may arise when using
Spanning Tree and VLANs. The Spanning Tree can use alternative
paths (such as different ports) to get messages to their destination.
VLANs specify which ports can receive messages.
Warning
When using the Spanning Tree facility, only use one
VLAN. If you do use two or more VLANs, this may
cause unexpected changes in your network topology.
Policy-based VLANs
This switch uses “Policy-based VLANs”. This means that the devices
attached to the switch can be grouped by any combination of MAC
address, IP address, IP subnet and port number; therefore, devices can
belong to one or more VLANs.
Policy hierarchy
If there is a conflict between two VLANs, there is a strict order of pri-
ority for the policies:
1. MAC address
2. IP address and IP Subnet and Mask
3. Switch ports
Warning
If a station belongs to a VLAN with a high priority pol-
icy (for example, MAC address), then it cannot belong
to another VLAN using a policy with a lower priority
(for example, port).