A network administrator connects two enterprise switches, Switch-Alpha and Switch-Beta, via an 802.1Q trunk link. Switch-Alpha is configured with a bridge priority of 28672 for VLAN 50, while Switch-Beta retains the default bridge priority of 32768 for VLAN 50. Additionally, the trunk port on Switch-Alpha has a native VLAN of 50, whereas the trunk port on Switch-Beta is configured with a native VLAN of 1. Which TWO of the following statements correctly describe the Layer 2 behavior and spanning tree status of this configuration?
- Switch-Alpha will be elected as the Spanning Tree Protocol (STP) Root Bridge for VLAN 50 because it possesses a lower numerical bridge priority than Switch-Beta.Answer
- A native VLAN mismatch error will occur because the native VLAN configurations on opposing ends of the 802.1Q trunk do not match.Answer
- CSwitch-Beta will be elected as the STP Root Bridge for VLAN 50 because STP favors higher numerical priority values during root selection.
- DHosts assigned to VLAN 10 on Switch-Alpha can directly communicate with hosts on VLAN 50 on Switch-Beta at Layer 2 without passing through a router.
- ESwitch-Alpha converts all Layer 2 Ethernet frames into Layer 3 IP packets prior to sending them across the trunk link.
Answer
The correct statements are that Switch-Alpha will be elected as the Spanning Tree Protocol (STP) Root Bridge for VLAN 50 due to its lower bridge priority, and a native VLAN mismatch error will be generated due to inconsistent native VLAN settings across the trunk link.
Switch-Alpha has a lower numerical bridge priority value (28672 vs 32768), which wins the STP root bridge election for VLAN 50. Simultaneously, configuring native VLAN 50 on one end of an 802.1Q trunk and native VLAN 1 on the other creates an operational native VLAN mismatch.
Step-by-Step Solution
Key Concept
STP Root Bridge Priority Selection and 802.1Q Native VLAN Trunk Consistency
Estimated Time:2m 0s