$cmd .= " -s $rule->{source}" if $rule->{source};
$cmd .= " -d $rule->{dest}" if $rule->{destination};
$cmd .= " -p $rule->{proto}" if $rule->{proto};
$cmd .= " -s $rule->{source}" if $rule->{source};
$cmd .= " -d $rule->{dest}" if $rule->{destination};
$cmd .= " -p $rule->{proto}" if $rule->{proto};