home  exhibition  quizzes  tour 
  basics  protocol mechanisms  internet  lans  applications  
  LAN mechanisms
token ring | spanning tree | ARP | IP-MAC | CSMA vs CSMA/CD | bridging | VLAN | collision domain |
 
search  
glossary  
projects  
sitemap  
contact  

Spanning Tree

Multiple redundant paths between LAN segments can greatly improve fault tolerance. But, unfortunately, multiple paths have a serious side effect: frames can cycle and multiply within the interconnected LANs. To prevent this, bridges communicate with each other in order to determine a spanning tree. Data is sent along this spanning tree topology -a subset of the original topology- that has no loops.

Once the bridges determine a spanning tree, they virtually disable appropriate interfaces or a whole bridge in order to create the spanning tree out of the real topology. If one of the links in the spanning tree fails, the bridges run the spanning tree algorithm again and determine a new tree structure.
The application guides you step by step through the spanning tree algorithm.