Avaya Cajun P882 - Manual (Page 59)

Cajun P550R/P880/P882 Switch User Guide
Introduction to the Cajun P550R/P880/P882 Switch
1-21
Spanning Tree
Protocol Bridge
Options All three switches support the following four Spanning Tree Protocol
options:
■
IEEE 802.1D Spanning Tree
■
Per-VLAN Spanning Tree
■
Dual-Layer Spanning Tree (Figure 1-4)
■
Global Disable
Figure 1-4. Spanning Tree Models
IEEE802.1D Spanning Tree Protocol Option
All three switches participate in a Single Spanning Tree domain in
the IEEE802.1D STP mode. All ports with STP configured belong to
the same spanning tree domain and rules are as defined in
IEEE802.1D unless otherwise specified herein. BPDUs are as defined
by 802.1D and are sent out Clear on each link regardless of whether
or not the link has a tagging method defined. This method is desired
when only a single VLAN is used in the network or when every
VLAN exists on every tagged inter-switch link and simplicity is a
major design goal.
Single 802.1D Spanning Tree
One Spanning Tree
Longer convergence
One path to and from root for all VLANs
Improper configuration
can shut down Trunk Links
Multi-Level Spanning Tree
Backbone terminates 802.1D STP
Smaller STP Domains
Quicker Convergence
VLAN Load Balancing
Interoperates w/ existing Bridge/Routers