Version Interoperability Fallback

Overview:

• Different standards of STP come with different approaches in handling convergence time guidelines
• RSTP switches are capable of pairing up with older or low-end switches running the original 802.1D Spanning Tree standard but with a cost of the enhancement features of RSTP. In these types of scenarios, the RSTP port directly connected to the STP neighbor port must fallback to 802.1D Spanning Tree standard as both standards operate using different sets of rules and convergence guidelines

Version Interoperability Demonstration

In this lab scenario, AccessSW1 is running in RPVST mode whereas DistroSW2 is running in PVST mode.

Interface Gi0/2 on AccessSW1 must fallback to using PVST as it is connected to a neighbor switch running an older standard of Spanning Tree.

Verifying the port falling back to the older Spanning Tree standard, the Gi0/2 port on the access switch has the port type set to 'P2p Peer(STP)' referring to the RPVST port falling back to the original Spanning Tree standard.