How to get the client's IP address in php?

1. If no proxy server is used

REMOTE_ADDR = Client IP

HTTP_X_FORWARDED_FOR = No value or not displayed

$ip = $_SERVER['REMOTE_ADDR'];

2. Use transparent proxy

REMOTE_ADDR = Last proxy server IP

HTTP_X_FORWARDED_FOR = client's real IP (when passing through multiple proxy servers, this value is similar: 221.5.252.160, 203.98.182.163, 203.129.72.215)

This type of proxy will also send the client's real IP to the request object , the real IP cannot be hidden.

$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];

3. Use ordinary anonymous proxy server

REMOTE_ADDR = Last proxy server IP

HTTP_X_FORWARDED_FOR = Proxy server IP (When passing through multiple proxy servers, this value is similar: 203.98.182.163, 203.98.182.163, 203.129.72.215)

This hides the real IP of the client , but the server will know that the client accesses through the proxy server.

4. Use deceptive proxy server

REMOTE_ADDR = Proxy server IP

HTTP_X_FORWARDED_FOR = Random IP (When passing through multiple proxy servers, this value is similar: 220.4.251.159, 203.98.182.163, 203.129.72.215)

The server can identify when passing the proxy server accessed, but the fake IP sent to the target server.

5. Use a high-anonymity proxy

REMOTE_ADDR = Proxy server IP

HTTP_X_FORWARDED_FOR = No The value may not be displayed

When using this kind of proxy, different browsers and different devices will return different IP header information, so PHP uses $_SERVER["REMOTE_ADDR"], $_SERVER[" HTTP_X_FORWARDED_FOR"] The value obtained may be a null value or an "unknown" value.

PHP obtains the ip code as follows:

public function ip() {
    //strcasecmp 比较两个字符，不区分大小写。返回0，>0，<0。
    if(getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), 'unknown')) {
        $ip = getenv('HTTP_CLIENT_IP');
    } elseif(getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), 'unknown')) {
        $ip = getenv('HTTP_X_FORWARDED_FOR');
    } elseif(getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), 'unknown')) {
        $ip = getenv('REMOTE_ADDR');
    } elseif(isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknown')) {
        $ip = $_SERVER[&#39;REMOTE_ADDR&#39;];
    }
    $res =  preg_match ( '/[\d\.]{7,15}/', $ip, $matches ) ? $matches [0] : '';
    echo $res;
    //dump(phpinfo());//所有PHP配置信息
}

For more PHP related knowledge, please visit PHP Chinese website!

The above is the detailed content of How to get the client's IP address in php?. For more information, please follow other related articles on the PHP Chinese website!