sub _compare_match_WWPN {

    die "no parameter!\n" unless @_;
    my ($w_ref) = @_;
   
    for my $name (@{ $w_ref }){

        my $found;

        for my $rmtkey (sort keys %wwns){
            if (grep {$name eq $_} @{ $wwns{$rmtkey} }){
                print "Found '${name}' that belongs to $rmtkey\n";
                $found = 1;
                last;
            }
        }
        if (! $found){
            print "$name not found!\n";
        }
    }
    return;
}