C
HAPTER
8
| Spanning Tree Algorithm
Overview
– 215 –
Figure 88: MSTP Region, Internal Spanning Tree, Multiple Spanning Tree
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 – see
"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 89: Common Internal Spanning Tree, Common Spanning Tree,
Internal Spanning Tree
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).
Region 1
Region 4
Region 2
Region 3
CIST
IST
Region 1
Region 4
Region 2
Region 3
CST
Summary of Contents for DG-GS4826S
Page 2: ...DG GS4826S DG GS4850S E012011 R01 F1 2 2 0 ...
Page 4: ......
Page 6: ...ABOUT THIS GUIDE 6 ...
Page 60: ...SECTION I Getting Started 60 ...
Page 72: ...CHAPTER 1 Introduction System Defaults 72 ...
Page 90: ...CHAPTER 2 Initial Switch Configuration Managing System Files 90 ...
Page 92: ...SECTION II Web Configuration 92 u Unicast Routing on page 539 u Multicast Routing on page 595 ...
Page 138: ...CHAPTER 4 Basic Management Tasks Resetting the System 138 ...
Page 204: ...CHAPTER 6 VLAN Configuration Configuring MAC based VLANs 204 ...
Page 212: ...CHAPTER 7 Address Table Settings Clearing the Dynamic Address Table 212 ...
Page 238: ...CHAPTER 9 Rate Limit Configuration 238 Figure 106 Configuring Rate Limits ...
Page 268: ...CHAPTER 12 Quality of Service Attaching a Policy Map to a Port 268 ...
Page 368: ...CHAPTER 14 Security Measures DHCP Snooping 368 ...
Page 422: ...CHAPTER 15 Basic Administration Protocols Remote Monitoring 422 ...
Page 488: ...CHAPTER 17 IP Configuration Setting the Switch s IP Address IP Version 6 488 ...
Page 538: ...CHAPTER 20 IP Services Forwarding UDP Service Requests 538 ...
Page 594: ...CHAPTER 21 Unicast Routing Configuring the Open Shortest Path First Protocol Version 2 594 ...
Page 624: ...CHAPTER 22 Multicast Routing Configuring PIMv6 for IPv6 624 ...
Page 638: ...CHAPTER 23 Using the Command Line Interface CLI Command Groups 638 ...
Page 712: ...CHAPTER 26 SNMP Commands 712 ...
Page 720: ...CHAPTER 27 Remote Monitoring Commands 720 ...
Page 776: ...CHAPTER 29 Authentication Commands Management IP Filter 776 ...
Page 876: ...CHAPTER 34 Port Mirroring Commands Local Port Mirroring Commands 876 ...
Page 898: ...CHAPTER 37 Address Table Commands 898 ...
Page 998: ...CHAPTER 41 Quality of Service Commands 998 ...
Page 1060: ...CHAPTER 42 Multicast Filtering Commands MLD Proxy Routing 1060 ...
Page 1078: ...CHAPTER 43 LLDP Commands 1078 ...
Page 1088: ...CHAPTER 44 Domain Name Service Commands 1088 ...
Page 1164: ...CHAPTER 47 IP Interface Commands IPv6 to IPv4 Tunnels 1164 ...
Page 1260: ...CHAPTER 48 IP Routing Commands Open Shortest Path First OSPFv3 1260 ...
Page 1304: ...SECTION IV Appendices 1304 ...
Page 1310: ...APPENDIX A Software Specifications Management Information Bases 1310 ...
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