SMC Networks SMC6624M manual Spanning Tree Protocol STP, STP Features Default Menu

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Configuring Advanced Features

Spanning Tree Protocol (STP)

Spanning Tree Protocol (STP)

STP Features

Feature	Default	Menu	CLI	Web
viewing the STP configuration	n/a	page	page	—
		9-100	9-102
enable/disable STP	disabled	page	page	page
		9-100	9-103	9-105
reconfiguring general operation	priority: 32768	page	page
	max age: 20 s	9-100	9-103
	hello time: 2 s
	fwd. delay: 15 s
reconfiguring per-port STP	path cost: var	page	page
	priority: 128	9-100	9-104
	mode: norm
monitoring STP	n/a	page	page	n/a
		10-14	10-15

The switch uses the IEEE 802.1D Spanning Tree Protocol (STP), when enabled, to ensure that only one path at a time is active between any two nodes on the network. In networks where there is more than one physical path between any two nodes, STP ensures a single active path between them by blocking all redundant paths. Enabling STP is necessary in such networks because having more than one path between a pair of nodes causes loops in the network, which can result in duplication of messages, leading to a “broad- cast storm” that can bring down the network.

You should enable STP in any switch that is part of a redundant physical link (loop topology). (It is recommended that you enable STP on all switches belonging to a loop topology.) This topic is covered in more detail under “How STP Operates” on page 9-105.

As recommended in the IEEE 802.1Q VLAN standard, the SMC6624M uses single-instance STP; a single spanning tree is created to make sure there are no network loops associated with any of the connections to the switch, regardless of whether VLANs are configured on the switch. Thus, these switches do not distinguish between VLANs when identifying redundant physical links. If VLANs are configured on the switch, see “STP Operation with 802.1Q VLANs” on page 9-107.

Features Configuring Advanced

9-99