Sometimes it is essential to perform scans in an anonymous manner. The firewall and IDS logs can reveal your IP address if you perform a scan without using security measures. One such feature is provided in Nmap, called decoy (-D).
The decoy option does not prevent your IP address from getting recorded in the log file of firewalls and IDS, but it does make the scan look scary. It adds other torrents in the log files, thus creating an impression that there are several other attackers scanning the machine simultaneously. So, if you add two decoy IP addresses, the log file will show that the request packets were sent from three different IP addresses; one will be yours and the other two will be the fake addresses added by ...
