Computer conversations consist of apparently random binary data. Therefore, network wiretap programs also come with a feature known as “protocol analysis”, which allow them to “decode” the computer traffic and make sense of it. We don’t directly need to break in to actual communication, we can install device on network and tap other network’s conversation which is the other advantage of packet Sniffer.
This shared technology is known as promiscus mode in sniffing, but bad news for black hats is this shared technology is getting transferred to Non-promiscus mode which is making it harder for intruder to install the sniffing programs.Internet is place where no place is available to see the all communication. Means we need to concentrate on single communication at a time. This architecture of internet prevents any single point of packet sniffing.
If we have two machines in our own office talking to each other, and both are on the Internet. They take a direct route of communication, and the traffic never goes across the outside public portion of the Internet. Any communication anywhere in the net follows a similar “least-cost-path” principle. Ethernet was built around a “shared” principle: all machines on a local network share the same wire.
This scenario implies that all the machines are able to “see” all the traffic on the same wire. Therefore, the next Ethernet hardware is built with a “filter” that ignores all traffic that doesn’t belong to it. It does this by ignoring all frames whose MAC address doesn’t match their own. A wiretap program effectively turns off this filter, putting the Ethernet hardware into “promiscuous mode”. MAC works on non promiscus mode and so only that traffic can be heard who is on same Ethernet wire. Like victim and intruder should share same Ethernet wire to make any attack possible.
To be Continued in Next Post . . .