Configure Mstp - Huawei Quidway S3500 Series Operation Manual

Operation Manual - STP
Quidway S3500 Series Ethernet Switches
Upon the initiation of the network, all the switches regard themselves as the roots. The
designated ports send the configuration BPDUs of local ports at a regular interval of
HelloTime. If it is the root port that receives the configuration BPDU, the switch will
enable a timer to time the configuration BPDU as well as increase MessageAge carried
in the configuration BPDU by certain rules. If a path goes wrong, the root port on this
path will not receive configuration BPDUs any more and the old configuration BPDUs
will be discarded due to timeout. Hence, recalculation of the spanning tree will be
initiated to generate a new path to replace the failed one and thus restore the network
connectivity.
However, the new configuration BPDU as now recalculated will not be propagated
throughout the network right away, so the old root ports and designated ports that have
not detected the topology change will still forward the data through the old path. If the
new root port and designated port begin to forward data immediately after they are
elected, an occasional loop may still occur. In RSTP, a transitional state mechanism is
thus adopted to ensure the new configuration BPDU has been propagated throughout
the network before the root port and designated port begin to send data again. That is,
the root port and designated port should undergo a transitional state for a period of
Forward Delay before they enter the forwarding state.
MSTP is compatible with STP and RSTP. The MSTP switch can recognize both the
STP and RSTP packets and calculate the spanning tree with them. Beside the basic
MSTP functions, Quidway Ethernet Switch Series also provide some features easy to
manage from the point of view of the users. These features include root bridge hold,
secondary root bridge, ROOT PROTECTION, BPDU PROTECTION, protocol hot
swapping, master/slave switchover, and so on.

1.2 Configure MSTP

MSTP configuration includes:
Configure the MST region for a switch
Specify the switch as primary or secondary root switch
Configure the MSTP running mode
Configure the Bridge priority for a switch
Configure the max hops in an MST region
Configure the switching network diameter
Configure the time parameters of a switch
Configure the max transmission speed on a port
Configure a port as an edge port
Configure the Path Cost of a port
Configure the priority of a port
Configure the port (not) to connect with the point-to-point link
Configure the mCheck variable of a port
Configure the switch security function
Huawei Technologies Proprietary
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Chapter 1 MSTP Region-configuration