source: [lemma=of] □ □
destination: [lemma=of] □ □ □
spec: Note : The use of parts of the console operating system 's IP address as part of the MAC address is an attempt to generate MAC addresses that are unique across different ESX Server machines . This poses an enormous challenge for journalists . It is good practice to keep a record of the MAC addresses that belong to particular pieces of hardware to assist in tracing network packets to their source . But there were very few of the terror-stricken people who attributed these doings to the agency of human hands .