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