Moxa Technologies EDS-726 user manual Configuring STP/RSTP

EDS-726 Series User’s Manual Featured Functions

The following figure shows an example of a network that contains VLANs 1 and 2. The VLANs are connected using the 802.1Q-tagged link between Switch B and Switch C. By default, this link has a port cost of 100 and is automatically blocked because the other Switch-to-Switch connections have a port cost of 36 (18+18). This means that both VLANs are now subdivided—VLAN 1 on Switch units A and B cannot communicate with VLAN 1 on Switch C, and VLAN 2 on Switch units A and C cannot communicate with VLAN 2 on Switch B.

	Switch A
100BaseTX	100BaseTX
full-duplex Link;	full-duplex Link;
only carries VLAN1	only carries VLAN2
(path cost = 18)	(path cost = 18)

Switch B	Switch C
	Block

802.1Q tagged, 10BaseTx half-duplex Link carries VLAN1, 2 (path cost = 100)

To avoid subdividing VLANs, all inter-switch connections should be made members of all available 802.1Q VLANs. This will ensure connectivity at all times. For example, the connections between Switches A and B, and between Switches A and C should be 802.1Q tagged and carrying VLANs 1 and 2 to ensure connectivity.

See the “Configuring Virtual LANs” section for more information about VLAN Tagging.

Configuring STP/RSTP

The following figures indicate which Spanning Tree Protocol parameters can be configured. A more detailed explanation of each parameter is given below the figure.

At the top of this page, the user can check the “Current Status” of this function. For RSTP, you will see:

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