Lantech LGS-2816C-RPS, User Manual

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P
ARAMETERS
These parameters are displayed on the Spanning Tree Protocol Status page:

Spanning Tree Protocol – Set 802.1W Rapid STP function Enable /
Disable. Default is ―Disable‖.

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 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.

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 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.

Max. Age - When the 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.

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.

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).