shadrack gave a good answer by using gethostbyaddr with the pack function to no use the Socket module which is tricky.
We normally would do : 
 
#!/usr/bin/perl
use Socket;

#Resolve IP address into hostname
sub ReverseLookup {
    my(@addrs,$xname,$xaliases,$xtype,$xlen,$addr);

#    @addrs=split(/\./,$_[0]);
#    $addr=pack('c4',@addrs[0..3]); # c or C - A signed/unsigned char 
+(8-bit integer) value
     $addr = inet_aton($_[0..3]);
    ($xname,$xaliases,$xtype,$xlen,@addrs)=gethostbyaddr($addr,2);
    return $xname;
}

[download]
We don't know why MonkeyManChfKiller don't want to use modules, it's his choice but obviously this can be achieved in another way with perl.
Nice use of pack() which I don't see very often.

In reply to Re^2: Net::Dns::packet creation. by cord-bin
in thread Net::Dns::packet creation. by MonkeyManChfKiller

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