– 133 –
C
HAPTER
4
| Configuring the Switch
Configuring the Spanning Tree Algorithm
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"
on page 137
). 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 47: Common Internal Spanning Tree, Common Spanning Tree,
Internal Spanning Tree
Region 1
Region 1
CIST
CST
IST
Region 4
Region 4
Region 2
Region 3
Region 2
Region 3
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).
C
ONFIGURING
G
LOBAL
S
ETTINGS FOR
STA
Use the STP Bridge Settings page to configure settings for STA which apply
globally to the switch.
P
ATH
Basic/Advanced Configuration, Spanning Tree, Bridge Settings
C
OMMAND
U
SAGE
◆
Spanning Tree Protocol
1
Uses RSTP for the internal state machine, but sends only 802.1D
BPDUs. This creates one spanning tree instance for the entire network.
If multiple VLANs are implemented on a network, the path between
specific VLAN members may be inadvertently disabled to prevent
network loops, thus isolating group members. When operating multiple
VLANs, we recommend selecting the MSTP option.
1.
STP and RSTP BPDUs are transmitted as untagged frames, and will cross any VLAN
boundaries.
Содержание EX26262
Страница 1: ...Layer 2 Gigabit PoE Ethernet Switch Management Guide...
Страница 2: ......
Страница 3: ...MANAGEMENT GUIDE...
Страница 4: ......
Страница 6: ...6 ABOUT THIS GUIDE...
Страница 18: ...18 FIGURES...
Страница 20: ...20 TABLES...
Страница 22: ...22 SECTION I Getting Started...
Страница 34: ...34 SECTION II Web Configuration...
Страница 46: ...46 CHAPTER 3 Using the Web Interface Navigating the Web Browser Interface...
Страница 202: ...CHAPTER 4 Configuring the Switch Quality of Service 202 Figure 83 Configuring Port Tag Remarking Mode...
Страница 290: ...290 CHAPTER 5 Monitoring the Switch Displaying Information About Flow Sampling...
Страница 294: ...CHAPTER 6 Performing Basic Diagnostics Running Cable Diagnostics 294...
Страница 300: ...CHAPTER 7 Performing System Maintenance Managing Configuration Files 300...
Страница 302: ...302 SECTION III Appendices...
Страница 320: ...GLOSSARY 320...
Страница 325: ......
Страница 326: ......