D-Link xStack DGS-3600 User Manual page 122

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
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.
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 Loopback Detection function on the Switch for
the ports configured above. For more information on this function, see the Loopback
Detection field in the STP Bridge Global Settings window, mentioned earlier in this section.
BPDU
Choosing True will allow the forwarding of BPDU packets in the specified ports from other
network devices. This will go into effect only if STP is globally disabled AND Forwarding BPDU
is globally enabled (See STP Bridge Global Settings above).
The default setting False, does not forward BPDU packets when STP is disabled.
Click Apply to implement changes made.
NOTE: If you want to enable Forwarding BPDU on a per port basis, the following settings must first be
in effect: 1. STP must be globally disabled and 2. Forwarding BPDU must be globally enabled. These
are the default settings configurable in the STP Bridge Global Settings menu discussed previously.
xStack DGS-3600 Series Layer 3 Gigabit Ethernet Managed Switch
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