protected void handleIncomingPacket(Ethernet_FramePayload frame, EthernetPacket ethernetPacket) {
        if (frame instanceof Ethernet_FramePayload_PnDcp) {
            PnDcp_Pdu pdu = ((Ethernet_FramePayload_PnDcp) frame).getPdu();
            if (pdu.getFrameIdValue() == 0xFEFF) {
                handlePnDcpPacket(pdu, ethernetPacket);
            }
        }
    }
This Discoverer makes use of part of the Profinet driver.
As every S7 device we know supports Profinet, we'll use the Profinet auto-discovery mechanism
and filter out the devices for which we know support the S7 comm protocol.
plc4j/drivers/s7/src/main/java/org/apache/plc4x/java/s7/readwrite/discovery/S7PlcDiscoverer.java