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SWT
GIGABIT/FAST ETHERNET SWITCH TYPE SWT
66/137
USER GUIDE - M0SWTA1903Iv09 - V09 March 2019
5.11
STP PROTOCOL CONFIGURATION
The Spanning Tree Protocol, in both its original version (STP) and the improved version
(RSTP) has the objective of identifying potential loops in level 2 networks, so that the
different equipment can communicate with each other and establish whether the different
interfaces in each will be active for switching client traffic, or on the contrary, whether they
will be used as backups in case of potential topological changes. The final result is that the
active interfaces of each equipment end up forming a tree structure with no loops from the
root equipment.
If the equipment is to be included in a level 2 network interconnected to other switching
equipment and there is a possibility of loops being created (depending on the connection
topology), it is ESSENTIAL to activate the Spanning Tree Protocol.
The specific equipment configuration parameters are:
•
Enable.
A simple checkbox parameter to indicate whether the STP must be
executed or not.
•
Version.
This establishes which of the possible protocol versions will be executed.
STP or RSTP (Rapid STP).
•
Bridge Priority.
This sets the priority of the equipment communicating with the root
equipment.
•
Max Age.
The maximum time during which the equipment considers the last BPDU
message received as valid. In the case of the stipulated time expiring, the
equipment assumes there has been a topological change and initiates the
topological change communication process. The default value is 20 seconds, and
the range admitted is between 6 and 40 seconds.
•
Hello Time.
This parameter establishes the time between sending BPDU
messages (the STP protocol messages). The default and maximum value is
2 seconds.
•
Forward Delay.
This parameter is the maximum period of time for an interface to
be in the listening and learning states. The default value for this period is 15
seconds, and the range admitted is between 4 and 30 seconds.
•
Tx Hold Count.
This establishes the maximum number of BPDU packets that can
be transmitted in one second. The default value is 6 and the admitted range is
between 1 and 10.