D-Link DES-3326S manual Spanning Tree, Parameter Description Default Value

DES-3326S Layer 3 Fast Ethernet Switch User’s Guide

Spanning Tree

The IEEE 802.1D Spanning Tree Protocol allows for the blocking of links between switches that form loops within the network. When multiple links between switches are detected, a primary link is established. Duplicated links are blocked from use and become standby links. The protocol allows for the duplicate links to be used in the event of a failure of the primary link. Once the Spanning Tree Protocol is configured and enabled, primary links are established and duplicated links are blocked automatically. The reactivation of the blocked links (at the time of a primary link failure) is also accomplished automatically – without operator intervention.

The DES-3326S STP allows two levels of spanning trees to be configured. The first level constructs a spanning tree on the links between switches. This is referred to as the Switch or Global level. The second level is on a port group basis. Groups of ports are configured as being members of a spanning tree and the algorithm and protocol are applied to the group of ports. This is referred to as the Port or VLAN level.

On the switch level, STP calculates the Bridge Identifier for each switch and then sets the Root Bridge and the Designated Bridges.

On the port level, STP sets the Root Port and the Designated Ports.

The following are the user-configurable STP parameters for the switch level:

	Parameter	Description	Default
			Value
Switch Management and Operating Concepts			59