Chapter 11 Spanning Tree Protocol
11.1.3 STP Port StatesSTP assigns five port states to eliminate packet looping. A bridge port is not allowed to go directly from blocking state to forwarding state so as to eliminate transient loops.
Table 23 STP Port States
PORT STATE | DESCRIPTION |
Disabled | STP is disabled (default). |
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Blocking | Only configuration and management BPDUs are received and processed. |
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Listening | All BPDUs are received and processed. |
| Note: The listening state does not exist in RSTP. |
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Learning | All BPDUs are received and processed. Information frames are submitted to the |
| learning process but not forwarded. |
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Forwarding | All BPDUs are received and processed. All information frames are received and |
| forwarded. |
MRSTP (Multiple RSTP) is ZyXEL’s proprietary feature that is compatible with RSTP and STP. With MRSTP, you can have more than one spanning tree on your Switch and assign port(s) to each tree. Each spanning tree operates independently with its own bridge information.
In the following example, there are two RSTP instances (MRSTP 1 and MRSTP2) on switch A.
To set up MRSTP, activate MRSTP on the Switch and specify which port(s) belong to which spanning tree.
"Each port can belong to one STP tree only.
Figure 46 MRSTP Network Example
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