fpdns - DNS server fingeprinting tool

       fpdns was written by Roy Arends and Jakob Schlyter.

fpdns is a program that remotely determines DNS server versions.  It does this by sending a series of
       borderline DNS queries which are compared against a table of responses and server versions.

       False positives or incorrect versions may be reported when trying to identify a set of servers residing
       behind a load-balancing apparatus where the servers are of different implementations, when a specific
       implementation behaves like a forwarder, behind a firewall without statefull inspection or without
       ApplicationIntelligence.

       fpdns - DNS server fingeprinting tool

-d   Enable debugging. Off by default.

       -D   Check all authoritative servers of the specified domain name.

       -f   Force checking of CH TXT version. Off by default.

       -Fnchild
            Maximum number of forked child processes. Defaults to 10.

       -pport
            Port to query remote nameserver on. Default is 53.

       -Qsrcaddr
            Set the source IP address to use.

       -rretry
            Number of attempt to retry fingerprints. Defaults to 1.

       -s   Short display form. Useful for surveys.

       -S   Separator. Defaults to " ".

       -ttimeout
            Set the query timeout in seconds. Defaults to 5.

       -T   Use TCP instead of UDP.

       -v   Show version of fpdns.

       server
            IP address or name to query. Alternatively may be '-' to read from a list of these from stdin

perl(1), Net::DNS(1)

perl v5.32.0                                       2021-01-04                                          FPDNS(1p)

fpdns [ -d ] [ -f ] [ -Fnchild ]
          [ -pport ] [ -Qsrcaddr ] [ -rretry ]
          [ -s ]  [ -Sseparator ] [ -ttimeout ] [ -v ] [server(s)]