Question

A network technician configures an 802.1Q trunk between two switches to carry VLANs 10, 20, and 30. VLAN 10 traffic passes correctly, but the switch logs report a native VLAN mismatch and untagged traffic is landing in the wrong VLAN. Switch A has the native VLAN set to 1, while Switch B has the native VLAN set to 99. What is the BEST way to resolve this issue?

Accepted Answer

Configure both switch trunk ports to use the same native VLAN

Answer

Enable STP on both trunk ports to block the mismatched VLAN

Answer

Add VLAN 99 to the allowed VLAN list on Switch A's trunk

Answer

Change the trunk encapsulation from 802.1Q to ISL on both switches