Configuration and principle of MSTP

1.RSTP

Traffic can not realize load sharing ： because STP perhaps RSTP It is necessary to block a link to achieve the effect of eliminating the loop , Then the blocked link will not forward user traffic , This will cause the problem of link bandwidth waste , Traffic can not achieve load balancing

Suboptimal path ： Because some links are blocked , Therefore, it may cause the problem of two-level optimal path

2. Basic concepts of spanning tree （ One ）

 MST region： Area , Be similar to ospf Region , There will be multiple instances in the region

3. Basic concepts of spanning tree （ Two ）

 MSTI： Multiple spanning tree instances , There will be multiple mapping tables in the instance , By default , All instances are not mapped to instances 0, Different instance The port role of is different

4. Basic concepts of spanning tree （ 3、 ... and ）

CSI： Common spanning tree , Is to connect all... In the switching network MST A spanning tree of the domain , If you put every MST Think of a domain as a node ,CST These nodes calculate and generate a spanning tree through the spanning tree protocol .

5. Basic concepts of spanning tree （ Four ）

IST: Internal spanning tree , The spanning tree in a region , Is to connect all... In the switching network MST A spanning tree of the domain , If you put every MST Think of a domain as a node ,CST These nodes calculate and generate a spanning tree through the spanning tree protocol .

6. Basic concepts of spanning tree （ 5、 ... and ）

CIST： Internal and public spanning trees , Calculate the generated by spanning tree protocol , A single spanning tree that connects all switching devices in a switching network . 

7. Basic concepts of spanning tree （ 6、 ... and ）

 SST： Single spanning tree , That is, the spanning tree with only one instance

8. Basic concepts of spanning tree （ 7、 ... and ）

Total root ： The whole one MSTP The best switch in the network

Domain root ： The switch closest to the total root

Main bridge ： Establish the switch closest to the total root in the domain

9. Summary

10. Port role  

master port ：Master The port is MST The port on the shortest path of all paths connected between the domain and the total root , It is connected to the switching device MST Port from domain to total root .

Master The port is the only way for messages in a domain to go to the total root

Master Ports are special domain edge ports ,Master Port in CIST The character on is Root Port, The role on each other is Master port

Domain edge port ： A domain edge port is located at MST The edge of the domain and connects the others MST Domain or SST The port of