Start the configuration with all ports and the default VLAN shutdown and disable GVRP and GMRP.
Tip - Dynamic VLAN learning is not a best practice.
Configure VLANs manually. You must add at least one port to a VLAN before you can assign a VLAN name.
Tip - In PVRST, set the port or port-channel in access or trunk mode first, then add the port or port-channel manually to assign a name to the VLAN.
Configure the priority of the default VLAN and external VLAN to a higher value than the default priority 32768.
Doing so makes the core switch become root even if the default and external VLANs are configured with the default priority in the core switch. Thus, only required traffic and not all core traffic reaches the ES1-24p-1 and ES1-24p-2 switches.