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Chapter 7
| Spanning Tree Algorithm
Configuring Loopback Detection
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183
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An MST Region consists of a group of interconnected bridges that have the same
MST Configuration Identifiers (including the Region Name, Revision Level and
Configuration Digest
–
“Configuring Multiple Spanning Trees”
). An
MST Region may contain multiple MSTP Instances. An Internal Spanning Tree (IST)
is used to connect all the MSTP switches within an MST region. A Common
Spanning Tree (CST) interconnects all adjacent MST Regions, and acts as a virtual
bridge node for communications with STP or RSTP nodes in the global network.
Figure 102: Spanning Tree
–
Common Internal, Common, Internal
Region 1
Region 1
MSTP connects all bridges and LAN segments with a single Common and Internal
Spanning Tree (CIST). The CIST is formed as a result of the running spanning tree
algorithm between switches that support the STP, RSTP, MSTP protocols.
Once you specify the VLANs to include in a Multiple Spanning Tree Instance (MSTI),
the protocol will automatically build an MSTI tree to maintain connectivity among
each of the VLANs. MSTP maintains contact with the global network because each
instance is treated as an RSTP node in the Common Spanning Tree (CST).
Configuring Loopback Detection
Use the Spanning Tree > Loopback Detection page to configure loopback
detection on an interface. When loopback detection is enabled and a port or trunk
receives
it’s
own BPDU, the detection agent drops the loopback BPDU, sends an
SNMP trap, and places the interface in discarding mode. This loopback state can be
released manually or automatically. If the interface is configured for automatic
loopback release, then the port will only be returned to the forwarding state if one
of the following conditions is satisfied:
◆
The interface receives any other BPDU except for
it’s
own, or;
◆
The interfaces’s link status changes to link down and then link up again,
or;
◆
The interface ceases to receive
it’s
own BPDUs in a forward delay interval.
Note:
If loopback detection is not enabled and an interface receives it's own BPDU,
then the interface will drop the loopback BPDU according to IEEE Standard 802.1w-
2001 9.3.4 (Note 1).
Содержание GEL-5261
Страница 14: ...14 Contents Glossary 551 Index 559...
Страница 26: ...26 Figures...
Страница 30: ...30 Section I Getting Started...
Страница 42: ...42 Section II Web Configuration IP Services on page 527...
Страница 45: ...Chapter 2 Using the Web Interface NavigatingtheWebBrowserInterface 45 Figure 1 Dashboard...
Страница 62: ...62 Chapter 2 Using the Web Interface NavigatingtheWebBrowserInterface...
Страница 180: ...Chapter 6 Address Table Settings Issuing MAC Address Traps 180...
Страница 208: ...Chapter 8 Congestion Control Storm Control 208 Figure 121 Configuring Storm Control...
Страница 218: ...218 Chapter 9 Class of Service Layer 3 4 Priority Settings Figure 128 Configuring DSCP to Queue Mapping...
Страница 228: ...228 Chapter 10 Quality of Service Attaching a Policy Map to a Port...
Страница 332: ...Chapter 12 Security Measures ARP Inspection 332 Figure 207 Displaying the ARP Inspection Log...
Страница 436: ...Chapter 13 Basic Administration Protocols LBD Configuration 436...
Страница 488: ...488 Chapter 14 Multicast Filtering Filtering MLD Query Packets on an Interface...
Страница 498: ...Chapter 15 IP Tools Address Resolution Protocol 498...
Страница 517: ...517 Chapter 16 IP Configuration Setting the Switch s IP Address IP Version 6 interface...
Страница 542: ...540 Section III Appendices...
Страница 560: ...Glossary 558...
Страница 569: ...567 Index web interface access requirements 43 configuration buttons 46 menu list 47 panel display 46...
Страница 570: ...568 Index E062017 ST R01...