VLANs

VLANs provide network managers with two significant capabilities:

• The ability to segment traffic in a flat switched network. This helps prevent traffic from being forwarded to stations where it is not needed.
• The ability to ignore physical switch locations when creating workgroups. VLANs are logical constructions and can traverse physical switch boundaries.

The hardware on all multiservice switches support port-based VLANs with the following characteristics:

• Frames classified as Layer 1 (port-based) when they enter the switch
• Explicitly tagged VLAN packets -- these are forwarded based on the information in the packet.
• Up to 1,000 VLANs -- VLANs define a set of ports in a flooding domain. Packets that need to be flooded are sent only to ports participating in that VLAN.

For more information on VLANs, see Chapter�6, "Using VLANs, Hunt Groups, and VTP Snooping."