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Spanning Tree Uplinkfast and Backbone Fast on Distribution Switches

Should uplinkfast also be enabled along with backbone fast on distribution switches?


Re: Spanning Tree Uplinkfast and Backbone Fast on Distribution S

UplinkFast provides fast STP convergence after a direct link failure in the network access-layer. It operates without modifying the STP protocol, and its purpose is to speed up convergence time in a specific circumstance less then 3 sec, rather than the typical 30s delay (for a direct link failure). Upon failure the blocking uplink is immediately moved to a forwarding state without waiting for listening and learning states. Use this on switches with blocked ports (usually the access layer but can be distribution).

BackboneFast provides rapid convergence from indirect link failures. By adding to the STP protocol, convergence times can typically be reduced from 50s to 30s. The mechanism is initiated when a root port or blocked port on a switch receives inferior BPDUs from its designated bridge - this can typically happen when a downstream switch has lost its connection to the root and starts sending BPDUs to elect a new root. This should be enabled on all switches.