ScriptxOne

      Get the Authority Dns Reverse Servers with a nice tool called Whois ; so then you can start a passive gathering from Multiples Hosts in a file caught by your IDS or IPS blacklist or from some secure source database on web , either if it has 80.000 hosts file , turning it into a powerful tool with pv and grep to your toolkit.   pv is a monitor to progress of data through a pipe or source, same as a more common tool DD, but pv offers some more options to Show Progress and Monitor  data transfer. Here, I'm using grep followed with -H to bring the Source File Name and -f option to insert a match list  in a file named Matchfile. apt-cache search whois # also check other tools as dmitry # Check WHOIS Flags Enabled :                     '-a' = All mirrored databases.                    '-d' = Return the Reverse DNS delegati...