Operation Manual – MSTP
H3C S9500 Series Routing Switches
Chapter 1 MSTP Configuration
1-16
Figure 1-5
Port roles
In
Figure 1-5
,
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 forwards user traffic;
z
Discarding: the port neither learns MAC addresses nor forwards user traffic.
Note:
When in different MSTIs, 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).
Table 1-6
Ports states supported by different port roles
Role
State
Root
port/Master
port
Designated
port
Alternate
port
Backup port
Forwarding
√
√
— —
Learning
√
√
— —
