User's Manual Part 2
Release8PlanningGuide
Issue2,November2007 Draft5forRegulatoryReview 165
14 ENGINEERINGVLANS
Cyclone radios support VLAN functionality as defined in the 802.1Q (Virtual LANs)
specification, except for the following aspects of that specification:
• the following protocols:
• Generic Attribute Registration Protocol (GARP) GARV
• Spanning Tree Protocol (STP)
• Multiple Spanning Tree Protocol (MSTP)
• GARP Multicast Registration Protocol (GMRP)
• priority encoding (802.1P) before Release 7.0
• embedded source routing (ERIF) in the 802.1Q header
• multicast pruning
• flooding unknown unicast frames in the downlink
As an additional exception, the Cyclone AP does not flood downward the unknown
unicast frames to the Canopy SM.
A VLAN configuration in Layer 2 establishes a logical group within the network. Each
computer in the VLAN, regardless of initial or eventual physical location, has access to
the same data. For the network operator, this provides flexibility in network segmentation,
simpler management, and enhanced security.
14.1 SMMEMBERSHIPINVLANS
With the supported VLAN functionality, Cyclone radios determine bridge forwarding on
the basis of not only the destination MAC address, but also the VLAN ID of the
destination. This provides flexibility in how SMs are used:
• Each SM can be a member in its own VLAN.
• Each SM can be in its own broadcast domain, such that only the radios that are
members of the VLAN can see broadcast and multicast traffic to and from the
SM.
• The network operator can define a work group of SMs, regardless of the AP(s)
to which they register.
Cyclone point-to-multipoint modules provide the VLAN frame filters that are described in
Table 36.