Moxa Technologies Moxa EtherDevice Switch EDS-405A - Manual (Page 47)

EDS-408A/405A Series User’s Manual Featured Functions
3-32
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.
Block
Switch A
Switch B Switch C
VLAN1
VLAN2
802.1Q tagged,
10BaseTx
half-duplex Link
carries VLAN1, 2
(path cost = 100)
100BaseTX
full-duplex Link;
only carries VLAN2
(path cost = 18) 100BaseTX
full-duplex Link;
only carries VLAN1
(path cost = 18)
VLAN1
VLAN2
VLAN1
VLAN2
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.
Configuring STP/RSTP
The following figures indicate the Spanning Tree Protocol parameters that can be configured. A
more detailed explanation of each parameter is given below the figure. (NOTE: The user interface
for EDS-408A shows 8 ports.)
At the top of this page, the user can check the Current Status of this function. For RSTP, you will
see: