How Can I Reliably Get and Store a Client's IP Address in PHP?

How to Get the Client IP Address in PHP for Reliable User Identification

When tracking user actions on your website, obtaining the client IP address is crucial. PHP provides several options for accessing this information.

The most reliable method is to utilize $_SERVER['REMOTE_ADDR']. This variable holds the genuine IP address of the connecting client.

However, be cautious of clients behind proxy servers. In such cases, the proxy may set $_SERVER['HTTP_X_FORWARDED_FOR']. While this value can provide additional information, it's inherently untrustworthy due to its susceptibility to spoofing.

To counter this, save both $_SERVER['HTTP_X_FORWARDED_FOR'] and $_SERVER['REMOTE_ADDR'] in separate database fields. This ensures the preservation of the original IP address for accountability.

Keep in mind that IP addresses in the newer IPv6 format can be up to 45 characters long. Therefore, allocate sufficient space in your database to accommodate this larger size. By employing these measures, you can effectively capture and store the client IP address for reliable user identification on your PHP website.

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