Basic running of the program:
./fierce.pl -dns <domain>
Search all class C ranges found for PTR records that match the domain
./fierce.pl -wide -dns <company>
Some reverse DNS looking
./fierce.pl -dnsserver <target_dns> -range <ipNet_range>
Some other flags:
-search -- search list. When fierce attempts to traverse up and down ipspace it may encounter other servers within other domains that may belong to the same company. If you supply a comma delimited list to fierce it will report anything found.
-threads <number> -- The number of threads to use when running the scan.
-wordlist <list.txt> -- Use an alternate word list to the default one for the application.
-file <filename.out> -- write the results of the scan to the file specified in the cmdline.
-delay <number> -- This specifies a delay, in seconds, to wait between queries.
