<?php
error_reporting(E_ALL);
$ip = "192.168.2.23";

$db = new mysqli('localhost', 'ban', 'Blubb123-', 'ban');
if ($db->connect_errno){
    die($db->connect_error);
}
$db->set_charset('utf8');
function set($ip,$db) {
    $dbAction = $db->prepare("INSERT INTO list (ip) VALUES (?) ON DUPLICATE KEY UPDATE count = count + 1");
    $dbAction->bind_param('i',$ip);
    return $dbAction->execute();
}
if(set(ip2long($ip),$db)){
    echo "inserted $ip" . PHP_EOL;
} else {
    echo "fehler" . PHP_EOL;
};