MicroNet Technology SP1659P - Manual (Page 39)

Parameter description:
y Spanning Tree Protocol:
Set 802.1W Rapid STP function Enable / Disable. Default is “Disable”
y Bridge Priority:
The lower the bridge priority is, the higher priority it has. Usually, the bridge with the highest bridge
priority is the root. If you want to have the 24 Gigabit L2 managed switch as root bridge, you can set
this value lower than that of bridge in the LAN. The valid value is 0 ~ 61440. The default is 32768.
y Hello Time:
Hello Time is used to determine the periodic time to send normal BPDU from designated ports among
bridges. It decides how long a bridge should send this message to other bridge to tell I am alive. When
the 24 Gigabit L2 managed switch is the root bridge of the LAN, for example, all other bridges will use
the hello time assigned by this switch to communicate with each other. The valid value is 1 ~ 10 in unit
of second.
Default is 2 seconds.
y Max. Age:
When the 24 Gigabit L2 managed switch is the root bridge, the whole LAN will apply this figure set by
this switch as their maximum age time. When a bridge received a BPDU originated from the root
bridge and if the message age conveyed in the BPDU exceeds the Max. Age of the root bridge, the
bridge will treat the root bridge malfunctioned and issue a Topology Change Notification (TCN) BPDU
to all other bridges. All bridges in the LAN will re-calculate and determine who the root bridge is. The
valid value of Max. Age is 6 ~ 40 seconds. Default is 20 seconds.
y Forward Delay:
You can set the root bridge forward delay time. This figure is set by root bridge only. The forward delay
time is defined as the time spent from Listening state moved to Learning state and also from Learning
state moved to Forwarding state of a port in bridge. The forward delay time contains two states,
Listening state to Learning state and Learning state to Forwarding state. It assumes that forward delay
time is 15 seconds, then total forward delay time will be 30 seconds. This has much to do with the STP
convergent time which will be more than 30 seconds because some other factors.
The valid value is 4 ~ 30 seconds, default is 15 seconds.
y Force Version:
Two options are offered for the user’s choosing STP algorithm. One is RSTP and the other is STP. If
STP is chosen, RSTP will run as a legacy STP. The switch supports RSTP (802.1w) which is backward
compatible with STP (802.1d).
38