A network administrator observes that network traffic across multiple VLANs is taking a sub-optimal path through a legacy access switch rather than the primary core switch. Output from `show spanning-tree` reveals that the legacy access switch is currently operating as the Spanning Tree Protocol (STP) Root Bridge because the primary core switch has a configured STP priority of 61440, while the access switch retains the default priority of 32768. Which configuration change on the core switch will resolve the issue and force it to become the STP Root Bridge?
- Lower the STP bridge priority value on the core switch to a value less than 32768 (such as 4096).Answer
- BIncrease the STP bridge priority value on the core switch to 65535 to give it maximum precedence.
- CConfigure a different native VLAN on the core switch trunk interfaces to force a topology recalculation.
- DMove each VLAN to a separate physical switch to eliminate Layer 2 broadcast domains entirely.
Answer
Lower the STP bridge priority value on the core switch to a value less than 32768 (such as 4096).
Spanning Tree Protocol uses the lowest Bridge ID (Priority + MAC address) to select the Root Bridge. Lowering the bridge priority value on the core switch below the access switch's priority (e.g., to 4096) ensures the core switch is elected Root Bridge, aligning traffic flow with the intended network design.
Step-by-Step Solution
Key Concept
STP Root Bridge Election and Priority Hierarchy
Estimated Time:1m 30s