search
HomeBackend DevelopmentPHP TutorialHow to get the real IP of the user client in PHP

How to get the real IP of the user client in PHP

Jan 02, 2018 pm 02:01 PM
phpclientreality

How does PHP get the real IP of the user client? Obtaining the client's IP is actually not a simple task. Because of IP spoofing and proxy problems, the authenticity of obtaining the client's IP will be compromised and cannot be 100% accurate. However, we try to use more complete methods to obtain the customer's IP. Below, the editor will share with you the method of obtaining the real IP of the user's client in PHP. I hope it will be helpful to everyone.

Obtaining the client IP is actually not a simple task. Because there are IP spoofing and proxy problems, the authenticity of obtaining the client IP will be compromised and cannot be 100% accurate. But we still try our best to find it. A relatively complete method of obtaining the real IP of the client. You can find many methods of obtaining the IP using PHP.

function getIp(){
if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
$ip = getenv("HTTP_CLIENT_IP");
else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
$ip = getenv("HTTP_X_FORWARDED_FOR");
else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown"))
$ip = getenv("REMOTE_ADDR");
else if (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))
$ip = $_SERVER['REMOTE_ADDR'];
else
$ip = "unknown";
return($ip);

Now we need to explain this code. Two functions are used here, getenv() and strcasecmp( ), the previous function obtains the system environment variable. If the value can be obtained, it returns the value, otherwise it returns false.

$_SERVER is the server super global variable array, use $_SERVER['REMOTE_ADDR'] You can also get the client's IP address. The difference between the two is that getenv does not support php running in IIS isapi mode.

strcasecmp(string1,string2) The usage of the string function is to compare string1 and string2 , if equal, return 0. If string1 is greater than string2, return a number greater than 0. If it is less, return a number less than 0.

The function first uses the customer IP. If it is not established, try to use the proxy method. If it does not work, use it again. REMOTE_ADDR.

I have also seen a more detailed method of detecting IP, which takes into account IP spoofing and multiple proxy codes. The method is similar.

function getip() {
$unknown = 'unknown';
if ( isset($_SERVER['HTTP_X_FORWARDED_FOR']) && $_SERVER['HTTP_X_FORWARDED_FOR'] && strcasecmp($_SERVER['HTTP_X_FORWARDED_FOR'], $unknown) ) {
$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
} elseif ( isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], $unknown) ) {
$ip = $_SERVER['REMOTE_ADDR'];
}
/*
处理多层代理的情况
或者使用正则方式:$ip = preg_match("/[\d\.]{7,15}/", $ip, $matches) ? $matches[0] : $unknown;
*/
if (false !== strpos($ip, ','))
$ip = reset(explode(',', $ip));
return $ip;
}

1. No proxy is used The server's PHP obtains the client IP:

REMOTE_ADDR = Client IP
HTTP_X_FORWARDED_FOR = No value or no display

2. When using a transparent proxy server :Transparent Proxies

REMOTE_ADDR = Last proxy server IP
HTTP_X_FORWARDED_FOR = Client 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 server still sends the client’s real IP to the access object, which cannot achieve the purpose of hiding the true identity.

3. Using ordinary anonymous proxy servers PHP obtains the client IP: Anonymous Proxies

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)

In this case, the real IP of the client is hidden, but it is revealed to the access object that the client uses a proxy server to access them.

4. The use of deceptive proxy servers: Distorting Proxies

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)

In this case, it is also revealed that the client uses a proxy server, but a fake random IP (220.4.251.159) is fabricated to replace the client’s real IP. Deceive it.

5. Use PHP of a high-anonymity proxy server to obtain the client IP: High Anonymity Proxies (Elite proxies)

REMOTE_ADDR = Proxy server IP

HTTP_X_FORWARDED_FOR = No value or not displayed

Whether it is REMOTE_ADDR or HTTP_FORWARDED_FOR, these header messages may not be available because different browsers and different network devices may send different IP header messages. Therefore, PHP The value obtained using $_SERVER["REMOTE_ADDR"] and $_SERVER["HTTP_X_FORWARDED_FOR"] may be a null value or an "unknown" value.

Related recommendations:

phpHow to calculate IP address mask

php IP Get City API (Innocent IP Database)

php IP and IP segment access restriction code_PHP tutorial

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

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Explain how load balancing affects session management and how to address it.Explain how load balancing affects session management and how to address it.Apr 29, 2025 am 12:42 AM

Load balancing affects session management, but can be resolved with session replication, session stickiness, and centralized session storage. 1. Session Replication Copy session data between servers. 2. Session stickiness directs user requests to the same server. 3. Centralized session storage uses independent servers such as Redis to store session data to ensure data sharing.

Explain the concept of session locking.Explain the concept of session locking.Apr 29, 2025 am 12:39 AM

Sessionlockingisatechniqueusedtoensureauser'ssessionremainsexclusivetooneuseratatime.Itiscrucialforpreventingdatacorruptionandsecuritybreachesinmulti-userapplications.Sessionlockingisimplementedusingserver-sidelockingmechanisms,suchasReentrantLockinJ

Are there any alternatives to PHP sessions?Are there any alternatives to PHP sessions?Apr 29, 2025 am 12:36 AM

Alternatives to PHP sessions include Cookies, Token-based Authentication, Database-based Sessions, and Redis/Memcached. 1.Cookies manage sessions by storing data on the client, which is simple but low in security. 2.Token-based Authentication uses tokens to verify users, which is highly secure but requires additional logic. 3.Database-basedSessions stores data in the database, which has good scalability but may affect performance. 4. Redis/Memcached uses distributed cache to improve performance and scalability, but requires additional matching

Define the term 'session hijacking' in the context of PHP.Define the term 'session hijacking' in the context of PHP.Apr 29, 2025 am 12:33 AM

Sessionhijacking refers to an attacker impersonating a user by obtaining the user's sessionID. Prevention methods include: 1) encrypting communication using HTTPS; 2) verifying the source of the sessionID; 3) using a secure sessionID generation algorithm; 4) regularly updating the sessionID.

What is the full form of PHP?What is the full form of PHP?Apr 28, 2025 pm 04:58 PM

The article discusses PHP, detailing its full form, main uses in web development, comparison with Python and Java, and its ease of learning for beginners.

How does PHP handle form data?How does PHP handle form data?Apr 28, 2025 pm 04:57 PM

PHP handles form data using $\_POST and $\_GET superglobals, with security ensured through validation, sanitization, and secure database interactions.

What is the difference between PHP and ASP.NET?What is the difference between PHP and ASP.NET?Apr 28, 2025 pm 04:56 PM

The article compares PHP and ASP.NET, focusing on their suitability for large-scale web applications, performance differences, and security features. Both are viable for large projects, but PHP is open-source and platform-independent, while ASP.NET,

Is PHP a case-sensitive language?Is PHP a case-sensitive language?Apr 28, 2025 pm 04:55 PM

PHP's case sensitivity varies: functions are insensitive, while variables and classes are sensitive. Best practices include consistent naming and using case-insensitive functions for comparisons.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SublimeText3 English version

SublimeText3 English version

Recommended: Win version, supports code prompts!

SecLists

SecLists

SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor