Intel NetStructure 470 - Manual (Page 22)

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C H A P T E R 2 Intel® NetStructure™ 470T and 470F Switches User Guide
Protocol-based VLANs
In a protocol-based VLAN, traffic is bridged through specified ports based
on its protocol. Any packet using a different protocol is dropped as it enters
the switch. This type of VLAN allows you to use a common protocol to
communicate, yet prevents any packets that are not using the specified
protocol, from entering the switch.
For example, you can attach a LAN using NetBEUI traffic to port 1 on the
switch, and attach a LAN using IPX traffic to port 2 on the switch. Then,
attach a router connected to the Internet, to port 8. Create an IP VLAN that
incorportates ports 1, 2, and 8. The NetBEUI traffic on port 1is not passed
to ports 2 or 8. The IPX traffic on port 2 is not passed to ports 1 or 8.
However, computers using the IP protocol can talk freely to ports 1, 2, and
8. This allows the computers to connect to the Internet, yet not be
bombarded with traffic that they do not need to see.
The 470 switches support a maximum of four protocol-based VLANs, and
they can be either IP, IPX, NetBEUI, or all three combined. Each port can
be a member of only one protocol-based VLAN. The example below shows
a 470F switch.
Protocol-based VLANs can help optimize network traffic patterns because
protocol-specific broadcast messages are sent only to computers that use
that protocol. For example, if a NetBEUI VLAN is created, only NetBEUI
traffic is allowed to pass through the VLAN.