PLANET FGSW-2620VM - Manual (Page 51)

FGSW-2620VM / FGSW-2624SF User’s Manual
On the switch level, STP calculates the Bridge Identifier for each switch and then sets the
Root Bridge and the Designated Bridges.
On the port level, STP sets the Root Port and the Designated Ports.
The following are the user-configurable STP parameters for the switch level:
Parameter Description Default Value
Bridge Identifier(Not user
configurable
except by setting priority below)
A combination of the User-set priority and the
switch’s MAC address.
The Bridge Identifier consists of two parts:
a 16-bit priority and a 48-bit Ethernet MAC address
32768 + MAC
32768 + MAC
Priority A relative priority for each switch – lower numbers
give a higher priority and a greater chance of a
given switch being elected as the root bridge
32768
Hello Time The length of time between broadcasts of the hello
message by the switch
2 seconds
Maximum Age Timer Measures the age of a received BPDU for a port
and ensures that the BPDU is discarded when its
age exceeds the value of the maximum age timer.
20 seconds
Forward Delay Timer The amount time spent by a port in the learning and
listening states waiting for a
BPDU that may return the port to the blocking state.
15 seconds
The following are the user-configurable STP parameters for the port or port group level:
Variable Description Default Value
Port Priority A relative priority for each
port –lower numbers give a higher priority and a
greater chance of a given port being elected as the
root port
32768
Port Cost A value used by STP to evaluate paths – STP
calculates path costs and selects the path with the
minimum cost as the active path
19-100Mbps Fast
Ethernet ports
4-1000Mbps Gigabit
Ethernet ports
Default Spanning-Tree Configuration
Feature Default Value
Enable state STP enabled for all ports
Port priority 128
Port cost 19
Bridge Priority 32,768
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