How to delete a VLAN that was mistakenly added to an H3C core switch port

To delete a VLAN from an H3C switch port, first remove it from all interfaces, then delete any VLAN interfaces, and finally remove the VLAN itself.

Step-by-Step Procedure

1. Access the Switch
   • Connect to the H3C switch via console, Telnet, or SSH.
   • Enter user view mode:

   • Enter system view:

     sys

2. Remove VLAN from Interfaces
   • Identify all interfaces where the VLAN is configured.
   • Enter each interface and remove the VLAN assignment. For example, to remove VLAN 20 from GigabitEthernet1/0/5:

     interface GigabitEthernet1/0/5[H3C-GigabitEthernet1/0/5] undo port access vlan 20

   • Repeat this step for all interfaces that have the VLAN configured .
3. Delete VLAN Interfaces
   • If a VLAN interface exists for the VLAN, delete it:

     undo interface Vlan-interface 20

   • This ensures that no Layer 3 interface remains associated with the VLAN .
4. Delete the VLAN
   • Finally, remove the VLAN from the switch:

     undo vlan 20

   • This deletes the VLAN from the VLAN database and frees up the VLAN ID for future use .

Important Notes

• VLAN 1 is the default VLAN and cannot be deleted.
• If the VLAN is configured on multiple interfaces, you must remove it from all interfaces before deleting the VLAN itself.
• Deleting a VLAN interface or VLAN may temporarily disrupt traffic for devices assigned to that VLAN, so plan accordingly.
• Use display vlan or display interface Vlan-interface to verify that the VLAN and its interfaces have been removed successfully . By following this sequence—remove VLAN from ports → delete VLAN interface → delete VLAN—you ensure a clean removal without residual configuration issues.