Virtual Lans And The At-Mux Protocol - Allied Telesis AT-2700FX Installation Manual

Virtual LANs and
the AT-MUX
Protocol
Note
The Installation CD that comes with your network adapter card has
two drivers for Microsoft Windows 2000, 2003, or XP system. There
is a regular driver and an enhanced driver that supports load
balancing and fail-over (LBFO) protection. The AT-Setup utility can
be used to install the regular driver. To install the LBFO driver, you
must install it manually. For further information, refer to "Load
Balancing and Fail-over Protection" on page 39 and "Choosing a
Network Adapter Card Driver" on page 58.
All of the adapters discussed in this guide are IEEE 802.1Q-compliant and
are designed to support virtual LANs (VLANs) and tagged packets. A
VLAN is an independent traffic domain where traffic generated by the
nodes of a VLAN is restricted only to nodes that are members of the same
VLAN. Traffic within a VLAN cannot cross over a VLAN boundary unless
there is an interconnection device, such as a router or a Layer 3 switch, in
the network.
VLANs are often used to group nodes with related functions into their own
separate, logical LAN segments. These VLAN groupings can be based on
similar data needs or security requirements. VLANs can increase network
performance and security by restricting traffic to specific devices or areas
of a network.
A tagged VLAN (IEEE 802.1Q) contains one or more network links that
carry traffic from more than one VLAN. The VLAN traffic is identified by a
header tag, or simply tag, that follows the source and destination
addresses in a packet. The tag contains a VLAN identifier (VID) that
uniquely identifies the VLAN to which a packet belongs.
The Allied Telesyn network adapter cards are capable of reading the
header tag in tagged packets as they arrive on the port, as well as adding
tags to packets when transmitting packets.
Before a network adapter card can handle tagged packets, you must
configure it by specifying the appropriate VIDs of the VLANs whose tagged
packets the adapter is to process.
There are two ways to add VIDs to a network adapter card in a Microsoft
Windows 2000, 2003, or XP system. If the card will be handling tagged
traffic from only one tagged VLAN, you can specify the VID using the
Network Connections window in Microsoft Windows, as explained in
"Configuring Additional Network Adapter Card Settings" on page 96.
If the network adapter card will be handling tagged traffic from more than
one VLAN, you can use the AT-MUX protocol, which is included on the
Installation CD shipped with the network adapter card. The protocol allows
you to assign up to 16 VIDs to a single adapter, enabling a network
Network Adapter Card Installation Guide
37