2) Using a sniffer, I can see that random packages sent to my IP address by all those bots and whatever that are out there, already know my MAC address without any communication from my part. This happens even when I start my internet connection and I have been online for only half a second, the first random bit of internet noise that hits me already knows my MAC address despite my not communicating with anyone besides my ISP to establish the connection. How does this work? Is my modem changing the MAC on incoming packets? Or my ISP?3) If I open my ISP monitoring window it shows me sent/received bytes to the internet. By carefully following this flow with the sniffer, I realized that there is a discrepancy, and that almost every packet sent/received, according to the sniffer, is 20 bytes longer than according to the ISP window. Any reason why (and which) 20 bytes would be underreported from every packet (almost every packet)? The ECHO packet behaves differently: my ISP window shows a flow of about 20 bytes per packet, while the sniffer program reports 50 to 60 bytes (don't remember the exact number).
4) Is there a website that will show you a print out of the packet you send it, the same way there are web sites that show you the details of your web request (such as IP address, what IE you're using, etc.)?