The following are the user-configurable STP parameters for the switch level:
Parameter
Bridge Identifier(Not user
configurable
except by setting priority
below)
Priority
Hello Time
Maximum Age Timer
Forward Delay Timer
The following are the user-configurable STP parameters for the port or port group level:
Variable
Port Priority
Port Cost
Default Spanning-Tree Configuration
Description
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
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
The length of time between broadcasts of the hello
message by the switch
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.
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.
Description
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
A value used by STP to evaluate paths –
STP calculates path costs and selects the
path with the minimum cost as the active
path
Feature
Enable state
Port priority
Port cost
Bridge Priority
User's Manual of IGS-5225 series
Default Value
128
200,000-100Mbps Fast Ethernet ports
20,000-1000Mbps Gigabit Ethernet
ports
0 - Auto
Default Value
STP disabled for all ports
128
0
32,768
149
Default Value
32768 + MAC
32768
2 seconds
20 seconds
15 seconds