Use the Net: dns cpan module to simulate a DNS cname response record

Install net: DNS Module

Perl-mcpan-e "Install net: DNS"

Script Simulation

#!/usr/bin/perluse Net::DNS::Nameserver;use strict;use warnings;sub reply_handler {     my ($qname, $qclass, $qtype, $peerhost,$query,$conn) = @_;     my ($rcode, @ans, @auth, @add);     print "Received query from $peerhost to ". $conn->{"sockhost"}. "\n";     $query->print;     if ($qtype eq "A" && $qname eq "www.ddos.com" ) {         my ($ttl, $rdata) = (3600, "10.1.2.3");         #push @ans, Net::DNS::RR->new("$qname $ttl $qclass $qtype $rdata");         push @ans, Net::DNS::RR->new("www.ddos.com 0 IN CNAME guard.ddos.com");         $rcode = "NOERROR";     }elsif( $qname eq "www.ddos.com" ) {         $rcode = "NOERROR";     }else{          $rcode = "NXDOMAIN";     }     # mark the answer as authoritive (by setting the 'aa' flag     return ($rcode, \@ans, \@auth, \@add, { aa => 1 });}my $ns = Net::DNS::Nameserver->new(            LocalPort    => 53,            ReplyHandler => \&reply_handler,            Verbose      => 1,            ) || die "couldn't create nameserver object\n";$ns->main_loop;

Execute scripts

Perl-W srv. pl