sub ip_add_num {
    my $self = shift;

    my ($value) = @_;

    my $ip = $self->intip + $value;

    my $last = $self->last_int;

    # Reached the end of the range ?
    if ($ip > $self->last_int) {
        return;
    }

    my $newb = ip_inttobin($ip, $self->version);
    $newb = ip_bintoip($newb, $self->version);

    my $newe = ip_inttobin($last, $self->version);
    $newe = ip_bintoip($newe, $self->version);

    my $new = new Net::IP("$newb - $newe");

    return ($new);
}