Virtual Bridging Functions; Vlan Functions - Lucent Technologies Cajun P220 Operation Manual

Overview of the P220 Gigabit Switch Family
17.6 Gbps total capacity.
Single copy replication. When possible, input frames destined for output on
multiple switch ports pass through the crossbar only once and are copied by the
crossbar to each destination.
Hardware-assisted multicast pruning. The switch forwards only to appropriate
destination switch ports.

Virtual Bridging Functions

The switch design supports:
Over 24,000 Media Access Control (MAC) addresses in the switch address
forwarding table. This feature allows the switch to store forwarding information for
hosts in very large networks.
Segmented address tables qualified by address and Virtual LAN (VLAN)
membership. This feature allows the same host to appear on different VLANs on
different ports.
Optional per-VLAN spanning tree. This isolates loop control to smaller domains, so
spanning trees converge faster during reconfiguration.

VLAN Functions

A VLAN (Virtual LAN) is a software defined group(s) of hosts on a local area network
(LAN) that communicate as if they were on the same wire, even though they are
physically on different LAN segments throughout a site.
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 P220 switch supports Layer 1, port-based VLANs, which have the following
characteristics:
Frames classified as they enter the switch using Layer 1 (Port-based).
Explicitly tagged VLAN packets are forwarded based on the information in the
packet. (See OpenTrunk Technology on page 2-5 for more information.)
Up to 1000 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.
2-4 Cajun P550/P220 Switch Operation Guide