What are the advantages and disadvantages of using IP-based blocking compared to referrer-based blocking in PHP?

When implementing blocking mechanisms in PHP, using IP-based blocking allows you to directly target specific users based on their IP address, providing a more direct and effective way to block unwanted traffic. On the other hand, referrer-based blocking relies on information provided by the HTTP referrer header, which can easily be manipulated or spoofed by malicious users, making it less reliable. 

// IP-based blocking
$blocked_ips = ['192.168.1.1', '10.0.0.1'];

if (in_array($_SERVER['REMOTE_ADDR'], $blocked_ips)) {
    // Block the user
    header("HTTP/1.1 403 Forbidden");
    exit();
}

// Referrer-based blocking
$blocked_referrers = ['example.com', 'malicious-site.com'];

$referrer = isset($_SERVER['HTTP_REFERER']) ? parse_url($_SERVER['HTTP_REFERER'], PHP_URL_HOST) : '';

if (in_array($referrer, $blocked_referrers)) {
    // Block the user
    header("HTTP/1.1 403 Forbidden");
    exit();
}

Keywords

IP-based blocking referrer-based blocking advantages disadvantages PHP

Related Questions