Allied Telesis AT-S29 - Manual (Page 121)

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Virtual LANs
Switches do not inherently support broadcast domains, which can lead
to broadcast storms in large networks that handle a lot of IPX traffic. In
conventional networks with routers, broadcast traffic is split up into
separate domains to confine broadcast traffic to the originating group
and provide a much cleaner network environment. By supporting
VLANS, this switch allows you to create segregated broadcast domains.
However, note that if you need to support intra-VLAN communications,
you must use a router or Layer 3 switch.
An IEEE 802.lQ 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,
but also allow you to make network changes without having to update
IP addresses or IP subnets. VLANs inherently provide a higher level of
network security, since traffic must pass through a Layer 3 switch or a
router to reach a different VLAN.
The AT-8324SX switch supports the following VLAN features:
❑ Up to 16 VLANs based on the IEEE 802.1Q standard
❑ Distributed VLAN learning across multiple switches using explicit
or implicit tagging and GARP/GVRP protocol
❑ Port overlapping, allowing a port to participate in multiple VLANs
❑ End stations can belong to multiple VLANs (so long as an end
station’s network interface card is 802.1Q compliant and is
configured for multiple VLANs)
❑ Passing traffic between VLAN-aware and VLAN-unaware devices
❑ Two-level priority queue
❑ Port trunking with VLANs