Specifications

Understanding and Configuring Loop Protect
March 14, 2011 Page 24 of 29
Figure 8 Basic Loop Protect Scenario
Figure 9showsthat,withoutLoopProtect,afailurecouldbeassimpleassomeoneaccidentally
disablingSpanningTreeontheportbetweenSwitch2and3.Switch3’sblockingporteventually
transitionstoaforwardingstatewhichleadstoaloopedcondition.
Figure 9 Spanning Tree Without Loop Protect
Figure 10showsthat,withLoopProtectenabled,Switch
3willnotgotoaforwardingstateuntilit
hasreceivedaBPDUfromSwitch2.
Figure 10 Spanning Tree with Loop Protect