User manual

ENGLISH
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An STP Group spanning tree works in the same way as the switch-level spanning tree, but the root bridge concept is
replaced with a root port concept. A root port is a port of the group that is elected based on port priority and port
cost, to be the connection to the network for the group. Redundant links will be blocked, just as redundant links
are blocked on the switch level.
The STP on the switch level blocks redundant links between switches (and similar network devices). The port level
STP will block redundant links within an STP Group.
It is advisable to define an STP Group to correspond to a VLAN group of ports.
The following fields can be set:
Parameter Description
From/To A consecutive group of ports may be configured starting with the selected port.
State Toggle from Disabled to Enabled to implement BPDU packet forwarding.
Cost (0 = Auto) 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 1-2000000 - Define a value between 1 and 2000000 to determine the
external cost. The lower the number, the greater the probability the port
will be chosen to forward packets.
Hello Time This can be set from 1 to 10 seconds. This is the interval between two transmissions of
BPDU packets sent by the Root Bridge to tell all other switches that it is indeed the Root
Bridge.
Migrate Setting this parameter as Yes will set the ports to send out BPDU packets to other
bridges, requesting information on their STP setting If the Switch is configured for RSTP,
the port will be capable to migrate from 802.1d STP to 802.1w RSTP. Migration should
be set as yes on ports connected to network stations or segments that are capable of
being upgraded to 802.1w RSTP on all or some portion of the segment.
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.
Click Apply to implement changes made.