What is the default time STP takes to converge from blocking to forwarding state?
15 seconds
The time spent in the listening and learning states is determined by a value known as the forward delay (default 15 seconds and set by the root bridge). If another switch is connected, the port may remain in blocking mode if it is determined that it would cause a loop in the network.
What is the purpose of the blocking state of ports in STP Spanning Tree Protocol )?
STP Port States Blocking – When a device is connected, the port will first enter the blocking state. Listening -The switch will listen for and send BPDUs. Learning – The switch will receive a superior BPDU, will stop sending its own BPDUs, and will relay the superior BPDUs. Forwarding – The port is forwarding traffic.
How does STP determine port selection?
Root Port selection is based on the port having lowest cost to the Root Bridge (CAT1). For PVST (Per VLAN Spanning Tree) path cost will depend on bandwidth of links and cost value is as shown below for most commonly used links.
Which ports go into a blocking state in the final step of the spanning tree algorithm?
The Switch Ports will go into a blocking state at the time of election process, when a switch receives a BPDU on a port that indicates a better path to the Root Switch (Root Bridge), and if a port is not a Root Port or a Designated Port.
Which of the following does a port do in the blocking state?
During blocking state, the port is only listening to and processing BPDUs on its interfaces. After 20 seconds, the switch port changes from the blocking state to the listening state.
What is port priority in STP?
When a loop occurs in a network topology, spanning tree can use the port priority value for the ports to decide which port must be put in forwarding state. The port priority is only used to determine the topology if the loop in the network cannot be resolved using bridge IDs or path cost.