User`s guide

Overview of Spanning Tree Protocols
Matrix DFE Series and N-SA User’s Guide 5-7
Figure 5-4 Example of Multiple Regions and MSTIs
Spanning Tree Port States
Spanningtreeassignsportstatestocontroltheforwardingandlearningprocesseswithina
topology.Table 5‐3listsSpanningTreeportstates,andthebehaviorassociatedwitheachstate:
Table 5-2 MSTI Characteristics for Figure 5-4
MSTI / Region Characteristics
MSTI 1 in Region 1 Root is Device 4, which is also the CIST regional root
MSTI 2 in Region 1 Root is Device 5
MSTI 1 in Region 2 Root is Device 7, which is also the CIST root
MSTI 1 in Region 3 Root is Device 11
MSTI 2 in Region 3 Root is Device 12
Device 10 is the CIST regional root
Region 1
12
34
5
Region 3
89
10 11
12
Region 2
6
7
Master Port Master Port
CIST
Regional Root
CIST Root
and CIST
Regional Root
CIST
Regional Root
Table 5-3 Spanning Tree Port States
Port State Behavior
Blocking Actively preventing traffic from using this path.
Listening Continuing to block traffic while waiting for protocol information to determine whether
to go back to the blocking state, or continue to the learning state.
Learning Learning station location information but continuing to block traffic.
Forwarding Forwarding traffic and continuing to learn station location information.
Disabled Disabled administratively or by failure.
Discarding MSTP state with the same behavior as blocking.