24-port NWay Ethernet Switch User’s Guide
Switch Management and Operating Concepts
43
(Not user-configurable
except by setting
priority below)
Bridge Identifier consists of two parts:
a 16-bit priority and a 48-bit Ethernet
MAC address
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
Table 5-1. STP Parameters – Switch Level
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
