The dnsenum.pl Perl script as described in its Perl documentation is a multithreaded script to enumerate information on a domain and to discover non-contiguous IP blocks. So the gist of dnsenum is to gather information about a specific domain using various sources. Information gathered about a domain includes sub domains, associated IP ranges, name servers, mx records, reverse DNS records, hostname IP addresses, and potential vulnerabilities via zone transfers. Below we go into detail regarding the switches available with dnsenum as well as what the command returns by default without and CLI switches.
While working on an upcoming article for QD I ran into an issue with the dnsenum.pl Perl script. I followed the process of installing the optional Perl modules and when I went back to test dnsenum it would no longer return any IP addresses. Instead of dnsenum returning actual IP addresses it was returning odd characters. It turns out there is some form of conflict between dnsenum.pl and the Net::DNS Perl module. Below I describe the dnsenum issue in more detail and provide a work around by manually downgrading the Net::DNS Perl module by hand.