A network administrator is troubleshooting an issue where workstations assigned to VLAN 30 on Switch-1 cannot communicate with servers on VLAN 30 attached to Switch-2. An audit of interface GigabitEthernet0/1 on Switch-1 reveals that it was mistakenly configured with static access mode (`switchport mode access`). Additionally, the trunk configuration documentation indicates VLAN 30 must be explicitly allowed, but the interface allowed list is currently restricted to VLANs 10 and 20 (`switchport trunk allowed vlan 10,20`).
Which TWO configuration commands must the administrator execute on Switch-1 interface GigabitEthernet0/1 to establish an 802.1Q trunk link and permit VLAN 30 traffic to pass across it?
- switchport mode trunkAnswer
- switchport trunk allowed vlan add 30Answer
- Cspanning-tree vlan 30 priority 4096
- Dip address 192.168.30.1 255.255.255.0
Answer
The correct commands are 'switchport mode trunk' and 'switchport trunk allowed vlan add 30'.
To establish proper Layer 2 trunking for VLAN 30, the port operational mode must first be changed from access to trunk using the trunk mode command. Secondly, because the trunk has an explicit allowed list restricting traffic, VLAN 30 must be added to the allowed VLAN list on the interface using the add keyword so it does not overwrite current allowed VLANs.
Step-by-Step Solution
Key Concept
802.1Q Trunking Mode Configuration and Allowed VLAN List Management