H3C S3610-28F, Operation Manual

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Operation Manual – MSTP
H3C S3610&S5510 Series Ethernet Switches
Chapter 1 MSTP Configuration
1-16
Connecting to the
common root bridge
Edge ports
Port 1
Port 2
Master port Alternate port
Designated port
Port 3 Port 4
Port 5
A
B
C
D
Port 6
Backup port
MST region
Figure 1-5 Port roles
Figure 1-5 helps understand these concepts. Where,
z
Devices A, B, C, and D constitute an MST region.
z
Port 1 and port 2 of device A connect to the common root bridge.
z
Port 5 and port 6 of device C form a loop.
z
Port 3 and port 4 of device D connect downstream to other MST regions.
11) Port states
In MSTP, port states fall into the following tree:
z
Forwarding: the port learns MAC addresses and forwards user traffic;
z
Learning: the port learns MAC addresses but does not forward user traffic;
z
Discarding: the port neither learns MAC addresses nor forwards user traffic.
Note:
When in different MST instances, a port can be in different states.
A port state is not exclusively associated with a port role. Table 1-6 lists the port state(s)
supported by each port role (“
√
” indicates that the port supports this state, while
“—“ indicates that the port does not support this state).