D-Link xStack DGS-3426 User Manual - page 119
xStack DGS-3400 Series Fast Ethernet Switch
The following STP Port Settings fields can be set:
Parameter
Description
From/To
A consecutive group of ports may be configured starting with the selected port.
External Cost < 0 = Auto>
This defines a metric that indicates the relative cost of forwarding packets to
the specified port list. Port cost can be set automatically or as a metric value.
The default value is 0 (auto).
0 (auto) - Setting 0 for the external cost will automatically set the speed for
forwarding packets to the specified port(s) in the list for optimal efficiency.
Default port cost: 100Mbps port = 200000. Gigabit port = 20000.
value 1-200000000 - Define a value between 1 and 200000000 to determine
the external cost. The lower the number, the greater the probability the port will
be chosen to forward packets.
Hello Time
The time interval between transmissions of configuration messages by the
designated port, to other devices on the bridged LAN. The user may choose a
time between 1 and 10 seconds. The default is 2 seconds. This field is only
operable when the Switch is enabled for MSTP.
Migration
When operating in RSTP mode, selecting yes forces the port that has been
selected to transmit RSTP BPDUs.
Edge
Choosing the True parameter designates the port as an edge port. Edge ports
cannot create loops, however an edge port can lose edge port status if a
topology change creates a potential for a loop. An edge port normally should
not receive BPDU packets. If a BPDU packet is received, it automatically loses
edge port status. Choosing the False parameter indicates that the port does
not have edge port status.
P2P
Choosing the True parameter indicates a point-to-point (P2P) shared link. P2P
ports are similar to edge ports, however they are restricted in that a P2P port
must operate in full duplex. Like edge ports, P2P ports transition to a
forwarding state rapidly thus benefiting from RSTP. A p2p value of False
indicates that the port cannot have p2p status. Auto allows the port to have
p2p status whenever possible and operate as if the p2p status were true. If the
port cannot maintain this status, (for example if the port is forced to half-duplex
operation) the p2p status changes to operate as if the p2p value were false.
The default setting for this parameter is true.
Forward BPDU
This drop-down menu allows you to enable or disable STP for the selected
group of ports. The default is Enabled.
State
This drop-down menu allows you to enable or disable STP for the selected
group of ports. The default is Enabled.
LBD
Use the pull-down menu to enable or disable the loop-back detection function
on the switch for the ports configured above.
Click Apply to implement changes made.
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