Installation manual

Operation Manual - STP
Quidway S3000-EI Series Ethernet Switches Chapter 1
MSTP Region-configuration
Huawei Technologies Proprietary
1-3
ot Bridge
IX. Edge
ort located at the MST region edge, connecting different
port on CIST instance should serve as a master
MSTI in the region.
X. Port
ne through which the data are forwarded to the
ream network segment or switch.
rt is the port connecting the entire region to the Common Root Bridge
aster port. When the master port is blocked,
The ned concepts for your better
e
VIII. Common Ro
The Common Root Bridge refers to the root bridge of CIST. There is only one common
root bridge in the specified network.
port
The edge port refers to the p
MST regions, MST region and STP region, or MST region and RSTP region. For MSTP
calculation, the edge port shall take the same role on MSTI and CIST instance. For
example, the edge port as a master
port on every
role
In the process of MSTP calculation, a port can serve as a designated port, root port,
master port, Alternate port, or BACKUP.
z The root port is the one through which the data are forwarded to the root.
z The designated port is the o
downst
z Master po
and located on the shortest path between them.
z Alternate port is the backup of the m
the alternate port will take its place.
z If two ports of a switch are connected, there must be a loop. In this case, the switch
will block one of them. The blocked one is called BACKUP port.
A port can play different roles in different spanning tree instances.
following figure illustrates the above mentio
und rstanding.
MST region
C
A
B
D
Port 4
Port 1
Port 2
Connected to the
common root
EdgePort
Master
port
Alternate port
Designated
port
Backup
port
Port 3
Port 5
Port 6
Figure 1-2 Port roles