ZyXEL XGS4700-48F User Guide - Page 151

STP Port States, Multiple RSTP

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Chapter 13 Spanning Tree Protocol 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. Table 27 STP Port States PORT STATE DESCRIPTION Disabled STP is disabled (default). Blocking Only configuration and management BPDUs are received and processed. Listening All BPDUs are received and processed. Learning Forwarding Note: The listening state does not exist in RSTP. All BPDUs are received and processed. Information frames are submitted to the learning process but not forwarded. All BPDUs are received and processed. All information frames are received and forwarded. 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. In the following example, there are two RSTP instances (MRSTP 1 and MRSTP2) on switch A. Figure 61 MRSTP Network Example To set up MRSTP, activate MRSTP on the Switch and specify which port(s) belong to which spanning tree. XGS4700-48F User's Guide 151

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Chapter 13 Spanning Tree Protocol
XGS4700-48F User’s Guide
151
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.
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.
In the following example, there are two RSTP instances (
MRSTP 1
and
MRSTP2
)
on switch
A
.
Figure 61
MRSTP Network Example
To set up MRSTP, activate MRSTP on the Switch and specify which port(s) belong
to which spanning tree.
Table 27
STP Port States
PORT
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.
Forwarding
All BPDUs are received and processed. All information frames are received
and forwarded.