GS-5220-Series (V4) User Manual

User’s Manual of GS-5220 PoE Series Managed Switch
168
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
128
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
200,000-100Mbps Fast Ethernet ports
20,000-1000Mbps Gigabit Ethernet
ports
0 - Auto
Default Spanning-Tree Configuration
Feature Default Value
Enable state STP disabled for all ports
Port priority 128
Port cost 0
Bridge Priority 32,768