Grading Checklist¶
A good response must include:
- Identifies the root cause: VLAN 350 is not in the allowed VLAN list on the trunk port to esxi-node-07
- Explains that trunk ports only carry VLANs explicitly allowed (or all VLANs if not restricted)
- Shows the command to check the trunk allowed VLAN list (e.g.,
show interface trunk,show running-config interface) - Notes that VLANs 100 and 200 work because they ARE in the allowed list
- Explains that tagged frames for VLAN 350 from the host are silently dropped by the switch
- Proposes the fix: add VLAN 350 to the trunk allowed VLAN list
- Mentions verifying that VLAN 350 exists in the switch VLAN database
- Suggests checking for VTP pruning as an alternative cause
- Recommends verifying with a ping test after applying the fix
- Points out that tcpdump on the host side showing tagged frames confirms the host config is correct
- Warns against using
switchport trunk allowed vlan allwithout understanding the security implications - Suggests documenting all required VLANs for new host deployments to prevent recurrence