ZyXEL Communications Plumbing Product metrogigabit switch User Manual
Chapter 13 Spanning Tree Protocol
MGS3700-12C User’s Guide
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13.1.3 STP Port States
STP 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.
allowed to go directly from blocking state to forwarding state so as to eliminate
transient loops.
13.1.4 Multiple RSTP
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.
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.
on switch A.
To set up MRSTP, activate MRSTP on the Switch and specify which port(s) belong
to which spanning tree.
to which spanning tree.
Table 26 STP Port States
PORT
STATE
STATE
DESCRIPTION
Disabled
STP is disabled (default).
Blocking
Only configuration and management BPDUs are received and processed.
Listening
All BPDUs are received and processed.
Note: The listening state does not exist in RSTP.
Learning
All BPDUs are received and processed. Information frames are submitted
to the learning process but not forwarded.
to the learning process but not forwarded.
Forwarding
All BPDUs are received and processed. All information frames are received
and forwarded.
and forwarded.