Error last ip address in info.network

[ddrv]

What steps will reproduce the problem?

<?php
/*
 * Some code
 */
$iptool = new Iptool($dbFile);
$info = $iptool->find($ip);
print_r($info);

What is the expected result?

Array
(
    [network] => Array
        (
            [first] => 114.12.70.0
            [last] => 114.12.70.255
        )
    ...
)

What do you get instead?

Array
(
    [network] => Array
        (
            [first] => 114.12.70.0
            [last] => 114.12.71.0
        )
    ...
)

Additional info

Q	A
IP Tool version	1.0.7
PHP version	7.0
Operating system	Linux Mint