ZyXEL Communications XGS-4528F - Manual (Page 109)

Chapter 11 Spanning Tree Protocol
XGS-4528F User’s Guide
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11.1.4 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 45 MRSTP Network Example
To set up MRSTP, activate MRSTP on the Switch and specify which port(s) belong to which
spanning tree.
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Each port can belong to one STP tree only.
11.1.5 Multiple STP
Multiple Spanning Tree Protocol (IEEE 802.1s) is backwards compatible with STP/RSTP and
addresses the limitations of existing spanning tree protocols (STP and RSTP) in networks to
include the following features:
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.
Table 25 STP Port States
PORT STATE DESCRIPTION