ZyXEL IPSubnettinq VLAN Support Notes

IPSubnetting VLAN

Ethernet Switch

ZyNOS 3.8

Support Notes

Version 3.80

September 2007

IPSubnetting VLAN

All contents copyright (c) 2007 ZyXEL Communications Corporation.

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Overview

Subnet based VLANs allow users to group traffic into logical VLANs based on the
source IP address and IP subnet. When a frame is received on a port, the switch
checks where the IP subnet it came from and what the source IP address is. The
untagged packets from the same IP subnet are then placed in the same subnet
based VLAN. The most significant advantage of using subnet based VLANs is that
the priority can be divided and tuned base on what VLAN the traffic belongs to.

Scenario

Considering the following topology:

Purpose:

Traffic from VoIP phone (source IP: 192.168.1.10) will be categorized into VLAN 3.

Traffic from IPTV (source IP: 192.168.5.10) will be categorized into VLAN 4.

Traffic from the PC (source IP: 192.168.10.10) will be categorized into VLAN 5.

IPSubnetting VLAN

All contents copyright (c) 2007 ZyXEL Communications Corporation.

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When there are different IP services requirement behind a modem (e.g. VoIP, IPTV,
and Common data networking). To separate the IP services in the edge site, we can
classify different VLANs for each IP service.

By distinguishing each service, Service Providers can do further policy controlling for
each VLAN.

In this topology, three IP services are needed by customer, VoIP, IPTV, and general
network access. Each client belongs to different IP subnets. We can achieve this
purpose using the switch with IPSubnetting VLAN function.