The Wandering Geek : /perl-script-reverse-dns.html

Thu, 01 Apr 2010

Updated - Perl Script that Does Bulk Reverse-DNS Lookups

I wrote a Perl script a few years ago that does bulk reverse-DNS lookups, and recently spent some time updating it. Quite handy for pen-testers, it can be used as part of the initial network discovery on a client's IP address space.

It uses the underlying CPAN modules more fully, and has some new features (from the code header):

Accepts IPv4/IPv6 addresses as singletons or a network in range or CIDR format
Allows you to configure which DNS server(s) to query
Allows you to configure a fixed delay between PTR lookups
Output to STDOUT for use in pipelines, or to a file in CSV or JSON format
Configurable timeout on PTR lookups
Persistent UDP connections to help lessen the load on DNS servers

You can get the updated script here - directions for running it are in the script header comments. I'd be interested in hearing about any problems or suggestions.

posted at: 20:39 | path: / | permanent link to this entry | 0 comments | tags: DNS Pentest Netsec Perl Code