Moxa Technologies EDS-510A, Moxa EtherDevice Switch user manual STP/RSTP Concept

EDS-510A Series User’s Manual			Featured Functions
Redundancy Protocol
	Setting	Description	Factory Default
	Turbo Ring	Select this item to change to the	None
		Turbo Ring configuration page.
	RSTP (IEEE	Select this item to change to the	None
	802.1W/1D)	RSTP configuration page.
Set as Master
	Setting	Description	Factory Default
	Enable/Disable	Select this EDS-510A as Master	None
Redundant Ports
	Setting	Description	Factory Default
	1st Port	Select any port of EDS-510A to be	Port G2 if enabled for
		one of the redundant ports.	Turbo Ring
	2nd Port	Select any port of EDS-510A to be	Port G3 if enabled for
		one of the redundant ports.	Turbo Ring
Enable Ring Coupling
	Setting	Description	Factory Default
	Enable/Disable	Select this EDS-510A as Coupler	None
Coupling Ports
	Setting	Description	Factory Default
	Coupling Port	Select any port of EDS-510A to be	Port 7 if enabled for
		the coupling port	Ring Coupling
	Coupling Control Port	Select any port of EDS-510A to be	Port G1 if enabled for
		the coupling control port	Ring Coupling

The STP/RSTP Concept

Spanning Tree Protocol (STP) was designed to help reduce link failures in a network, and provide protection from loops. Networks that have a complicated architecture are prone to broadcast storms caused by unintended loops in the network. Moxa EDS-510A’s STP feature is disabled by default. To be completely effective, you must enable RSTP/STP on every EDS-510A connected to your network.

Rapid Spanning Tree Protocol (RSTP) implements the Spanning Tree Algorithm and Protocol defined by IEEE Std 802.1w-2001. RSTP provides the following benefits:

yThe topology of a bridged network will be determined much more quickly compared to STP.

yRSTP is backward compatible with STP, making it relatively easy to deploy. For example:

¾Defaults to sending 802.1D style BPDUs if packets with this format are received.

¾STP (802.1D) and RSTP (802.1w) can operate on different ports of the same EDS-510A. This feature is particularly helpful when EDS-510A ports connect to older equipment, such as legacy switches.

You get essentially the same functionality with RSTP and STP. To see how the two systems differ, see the Differences between RSTP and STP section in this chapter.

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