PowerConnect B-Series FCX Configuration Guide
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802.1s Multiple Spanning Tree Protocol
8
FIGURE 56
MSTP configured network
The following definitions describe the STP instances that define an MSTP configuration.
Common Spanning (CST) – CST is defined in 802.1q and assumes one spanning-tree instance
for the entire bridged network regardless of the number of VLANs. In MSTP, an MSTP region
appears as a virtual bridge that runs CST.
Internal Spanning Tree (IST) – IST is a new terminology introduced in 802.1s. An MSTP bridge
must handle at least these two instances: one IST and one or more MSTIs (Multiple Spanning
Tree Instances). Within each MST region, the MSTP maintains multiple spanning-tree
instances. Instance 0 is a special instance known as IST, which extends CST inside the MST
region. IST always exists if the switch runs MSTP. Besides IST, this implementation supports up
to 15 MSTIs, numbered from 1 to 4094.
Common and Internal Spanning Trees (CIST) – CIST is a collection of the ISTs in each MST
region and the CST that interconnects the MST regions and single spanning trees.
Multiple Spanning Tree Instance (MSTI) – The MSTI is identified by an MST identifier (MSTid)
value between 1 and 4094.
MSTP Region – These are clusters of bridges that run multiple instances of the MSTP protocol.
Multiple bridges detect that they are in the same region by exchanging their configuration
(instance to VLAN mapping), name, and revision-level. Therefore, if you need to have two
bridges in the same region, the two bridges must have identical configurations, names, and
revision-levels. Also, one or more VLANs can be mapped to one MSTP instance (IST or MSTI)
but a VLAN cannot be mapped to multiple MSTP instances.
NOTE
One or more VLANs can be mapped to one MSTP instance (IST or MSTI) but a VLAN cannot be
mapped to multiple MSTP instances.
BigIron
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Switch 1
Switch 2
Switch 3
Switch 4
Switch 5
Switch 6
Switch 2
Switch 3
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Switch 5
Region 1
Region 2
Port2/1
Port2/2
Port2/3
Port2/3
Port2/1
Port2/1
Port1/2
Port1/1
Port1/3
Port1/4
Port1/2
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Port1/4
Port1/5
Port1/3
Port1/2
Port3/1
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Содержание PowerConnect B-FCXs
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Страница 136: ...94 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Viewing information about software licenses 4 ...
Страница 228: ...186 PowerConnect B Series FCX Configuration Guide 53 1002266 01 PowerConnect B Series FCX hitless stacking 5 ...
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Страница 230: ...188 PowerConnect B Series FCX Configuration Guide 53 1002266 01 PowerConnect B Series FCX hitless stacking 5 ...
Страница 248: ...206 PowerConnect B Series FCX Configuration Guide 53 1002266 01 IPv6 management commands 7 ...
Страница 346: ...304 PowerConnect B Series FCX Configuration Guide 53 1002266 01 802 1s Multiple Spanning Tree Protocol 8 ...
Страница 374: ...332 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Jumbo frame support 9 ...
Страница 424: ...382 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Virtual Switch Redundancy Protocol VSRP 10 ...
Страница 568: ...526 PowerConnect B Series FCX Configuration Guide 53 1002266 01 CLI examples 14 ...
Страница 588: ...546 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Sample application 15 ...
Страница 674: ...632 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Enabling or disabling layer 2 switching 19 ...
Страница 684: ...642 PowerConnect B Series FCX Configuration Guide 53 1002266 01 VLAN based mirroring 20 ...
Страница 724: ...682 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Reading CDP packets 23 ...
Страница 768: ...726 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Clearing cached LLDP neighbor information 24 ...
Страница 930: ...888 PowerConnect B Series FCX Configuration Guide 53 1002266 01 26 ...
Страница 948: ...906 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Configuring MLD snooping 27 ...
Страница 962: ...920 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Displaying CPU utilization statistics 28 ...
Страница 1022: ...980 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Displaying OSPF information 29 ...
Страница 1142: ...1100 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Clearing diagnostic buffers 30 ...
Страница 1258: ...1216 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Using Secure copy with SSH2 33 ...
Страница 1314: ...1272 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Displaying port security information 35 ...
Страница 1348: ...1306 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Example configurations 36 ...
Страница 1406: ...1364 PowerConnect B Series FCX Configuration Guide 53 1002266 01 IP source guard 39 ...
Страница 1422: ...1380 PowerConnect B Series FCX Configuration Guide 53 1002266 01 SNMP v3 Configuration examples 40 ...