Q3) What security advantage occurs from a packet’s containing the source NIC address and not just the destination NIC address?
Answers
Answer:
The message must travel from your computer to your router. Every computer connected to a network has a network interface card (NIC) with a unique physical address, called a MAC address (for Media Access Control). At the data link level, two more headers are added, one for your computer's NIC address (the source MAC) and one for your router's NIC address. A data link layer structure with destination MAC, source MAC, and data is called a frame. Every NIC selects from the network those frames with its own address as a destination address. The data link layer adds the structure necessary for data to get from your computer to another computer (a router is just a dedicated computer) on your network. Data Link Layer Transformation.
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