Three timers control STP behavior. Hello Time ( seconds default) is how often the root bridge sends BPDUs. Max Age ( seconds) is how long a switch waits without hearing BPDUs before assuming a failure. Forward Delay ( seconds) is how long a port stays in listening and learning states. Total convergence after a failure can take to seconds. These conservative timers were designed when networks were slower, but they feel painfully slow today.
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$ curl repovive.com/roadmaps/network-design/spanning-tree-and-link-aggregation/stp-timers-explained
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