FREE STP Configuration and Management Questions and Answers
What is the purpose of configuring a port’s cost in STP?
Port cost is used to determine the best path to the Root Bridge by influencing path preference in STP. Lower-cost paths are preferred over higher-cost ones, helping to prevent loops and optimize network traffic flow. Port cost does not affect port transition speed, Root Bridge selection, or BPDU transmission frequency.
Which STP variant is designed to provide faster convergence compared to traditional STP?
Rapid Spanning Tree Protocol (RSTP) provides faster convergence compared to traditional STP by improving the transition times between different port states. MSTP and CST are STP variants designed for multiple VLANs or specific topologies, and PVST is a variant of STP that runs a separate instance of STP for each VLAN but does not inherently speed up convergence.
What is the effect of configuring PortFast on a switch port?
PortFast enables a port to bypass the Listening and Learning states and transition directly to the Forwarding state, which speeds up the time it takes for a port to become active. PortFast does not prevent the port from participating in STP entirely; rather, it speeds up the process for edge ports where STP loop prevention is less critical.
What STP parameter can be adjusted to influence which switch becomes the Root Bridge?
The Bridge Priority, combined with the MAC address, determines the Bridge ID used to elect the Root Bridge. By adjusting the Bridge Priority, you can influence which switch is elected as the Root Bridge. Port Cost affects path selection, Forward Delay controls the time a port spends in different states, and Hello Time specifies the interval between BPDUs.
How can you verify the current STP configuration and status on a Cisco switch?
The show spanning-tree command provides detailed information about the STP configuration and status on a Cisco switch, including the Root Bridge, port roles, and STP timers. The show ip interface command displays interface details, show vlan shows VLAN information, and show mac-address-table displays MAC address entries.