Enable/disable L2PT (Layer 2 protocol tunneling) feature on the switch.
L2PT is used on the service provider's edge devices. L2PT allows edge switches
to tunnel layer 2 STP (Spanning Tree Protocol), CDP (Cisco Discovery Protocol)
and VTP (VLAN Trunking Protocol) packets between customer switches connected
through the service provider's network. The edge switch encapsulates layer 2
protocol packets with a specific MAC address before sending them across the
service provider's network to other edge switches.