I agree with you that Net::DNS is the way to go, but I also agree with the poster above that there's, many times, more than one PTR. Also, it would seem the parent poster is looking for PTR records, not A records. I sometimes lookup the A records for a PTR to see if they match...

UPDATE: After reading the update to the question I deleted much of this post and put this instead. It might even be what the asker wants, or close to it...

use strict;
use Net::DNS;

my $res = new Net::DNS::Resolver;
for my $rr ($res->axfr('domain.name')) {
    next unless $rr->type eq "A";

    my $host = $rr->name;
    my $ip   = $rr->address;

    next unless $ip eq "ip.ip.ip.ip";

    print "$host\n";
}
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