Switch Release Notes

Cajun P550 Switch Overview

1-12 Cajun P550/P220 Switch Operation Guide

Figure 1-7. Trunking Translation

Spanning Tree Models

Spanning trees are an IEEE 802.1 standard which provides distributed routing over

multiple LANs connected by bridges.

There are three spanning tree models:

❒

Single IEEE 802.1D spanning tree

❒

Spanning tree per VLAN

❒

Optimized “per-VLAN” spanning trees using a scalable, two-layer spanning tree

approach

Note: All models interoperate with legacy IEEE 802.1D bridges and switches.

Dual layer spanning trees provide two very important capabilities:

❒ Smaller spanning tree domains means much faster convergence during spanning

tree reconfiguration.

❒ Per-VLAN operation enables you to use more of the available bandwidth when you

have redundant links. A particular link can be blocked on one VLAN, but still

forward packets on another.

Frame

Format:

•“Clear”

•IEEE

802.1Q

•Multilayer

•3Com

Translation Function

Frame Format:

“Normal” - Ethernet

or 802.3 with valid

CRC