I am using php code to monitor all internet ip through chrome browser to my website

Confirm Expert: rcschroeder replied at 2025-03-02 21:21:53    

I'll address each of your questions step by step.

**When will Cloudflare use a proxy?**

Cloudflare uses a proxy to protect internet traffic in several scenarios:

1. **Traffic from known malicious IP addresses**: If you're using Cloudflare's security features, such as DDoS protection or IP filtering, and the incoming request comes from an IP address that's been flagged as malicious, Cloudflare will use a proxy to intercept and filter the request.
2. **Traffic from high-risk countries or regions**: Cloudflare may use a proxy for traffic coming from certain countries or regions that are known to have higher rates of cybercrime, such as North Korea or Iran.
3. **Traffic from suspicious sources**: If Cloudflare detects unusual patterns in incoming requests, such as rapid-fire requests or requests with unusual headers, it may use a proxy to intercept and analyze the traffic.
4. **Content delivery network (CDN) usage**: When using Cloudflare's CDN, the proxy is used to cache and distribute content across multiple servers, reducing latency and improving performance.

However, if you're not using any of these security features or settings, Cloudflare will not use a proxy by default.

**Case-1 vs Case-2: Why the difference?**

In your example, Case-1 and Case-2 differ in one key aspect:

* **HTTP_X_FORWARDED_FOR**: In Case-1, `$_SERVER['HTTP_X_FORWARDED_FOR']` contains your Computer A's ISP IP (`51.58.202.19`), which suggests that Cloudflare is using a proxy to filter incoming traffic from this IP address.
* **REMOTE_ADDR**: In Case-2, `$_SERVER['REMOTE_ADDR']` matches the `HTTP_X_FORWARDED_FOR` value, indicating that no proxy is being used.

This difference may be due to various factors, including:

* The fact that you're using Cloudflare's security features or settings, which might require additional filtering or proxying for specific IP addresses.
* Differences in your network configuration or ISP settings, which could affect how traffic is routed and filtered.

**When to use a proxy with Google Ads?**

When deciding whether to use a proxy with Google Ads, consider the following factors:

* **Ad security**: If you're using Cloudflare's ad protection features, such as the "Content Security Policy" (CSP), it may be necessary to use a proxy to protect ads from being intercepted or tampered with.
* **User privacy**: If you want to maintain user anonymity and prevent advertisers from tracking users across devices, using a proxy might be beneficial. However, this also means that ad performance and targeting may be affected.

In your case, if Cloudflare is using a proxy for Computer A's traffic, it's likely because of security or filtering concerns related to the ISP IP address. If you want to allow visitors from Computer A to click on ads without the proxy, consider disabling those features or adjusting your settings to use a different type of ad protection.

**Conclusion**

To summarize:

* Cloudflare uses proxies for traffic coming from known malicious IP addresses, high-risk countries or regions, suspicious sources, and when using CDN services.
* Case-1 and Case-2 differ due to differences in HTTP_X_FORWARDED_FOR values, suggesting that Cloudflare is using a proxy for Computer A's traffic.
* When deciding whether to use a proxy with Google Ads, consider ad security, user privacy, and potential performance implications.

If you're unsure about the best approach for your specific situation, consult Cloudflare's documentation or reach out to their support team for personalized guidance.

Confirm Expert: rcschroeder replied at 2025-03-02 20:48:25    

I'll answer your questions one by one.

**1. When Cloudflare will use proxy or not?**

Cloudflare uses a proxy to protect internet traffic when it detects suspicious activity, such as:

* An unusual number of requests from a single IP address
* Requests coming from an ISP (Internet Service Provider) that has been flagged for suspicious activity
* Requests coming from a VPN (Virtual Private Network) server
* Requests that are attempting to bypass Cloudflare's security features

In your case, Computer A is using a different ISP IP than Computer B, which might be the reason why Cloudflare uses a proxy for Computer A. However, since both PHP IPs are identical in both cases (`$_SERVER['HTTP_X_FORWARDED_FOR']=$_SERVER['REMOTE_ADDR']`), it's likely that Cloudflare is using a more sophisticated method to detect and mitigate traffic from specific ISPs or VPNs.

**2. Why doesn't Cloudflare use proxy for Computer B?**

There could be several reasons why Cloudflare doesn't use a proxy for Computer B:

* The ISP IP of Computer B might not match any suspicious patterns
* The requests coming from Computer B are legitimate and don't pose a security risk to Cloudflare's infrastructure
* Cloudflare has determined that the traffic from Computer B is coming from a trusted source (e.g., a legitimate user with an approved VPN)

Keep in mind that these are just hypotheses, and without more information, it's difficult to say for certain why Cloudflare treats each computer differently.

**3. Conditions under which Cloudflare uses or doesn't use proxy**

Here are some conditions under which Cloudflare might use or not use a proxy:

* **Uses proxy:**
+ Suspicious traffic from an ISP or VPN
+ Requests that bypass security features (e.g., a botnet)
+ Traffic coming from a known malicious IP address
* **Doesn't use proxy:**
+ Legitimate requests from trusted sources (e.g., approved VPNs, legitimate users)
+ Requests that are consistent with Cloudflare's expected traffic patterns

**4. Does using proxy indicate a malicious or suspicious IP?**

Using a proxy by Cloudflare does not necessarily mean the visitor's ISP IP is malicious or suspicious. However, it might be an indication of suspicious activity:

* If the proxy is used to mask the actual ISP IP, it could be a sign that the user is attempting to hide their true location or identity
* If the proxy is used to bypass security features, it could indicate that the user is using malicious software (malware) or a botnet

In summary, Cloudflare uses proxies to protect its infrastructure from suspicious traffic. The decision to use a proxy depends on various factors, including the ISP IP, request patterns, and security risk assessment.

Confirm Expert: rcschroeder replied at 2025-03-02 20:47:53    

I'll address your questions one by one.

**When Cloudflare will use proxy or not?**

Cloudflare uses proxies to protect internet traffic from various types of threats, including:

1. **Botnets**: Networks of compromised devices controlled by an attacker.
2. **Malicious IP addresses**: IPs known to be associated with malicious activity.
3. **DDoS attacks**: Distributed Denial of Service attacks that overwhelm a website or network.

When Cloudflare detects that an incoming request is coming from a suspicious or malicious IP address, it may use a proxy to:

1. Hide the original IP address of the visitor.
2. Filter out suspicious traffic.
3. Protect your website from potential DDoS attacks.

In your case, when Computer A's ISP IP (`51.58.202.19`) is identified as a trusted source by Cloudflare, it doesn't necessarily mean that the request is coming directly from this IP address. Instead, Cloudflare might be using its proxy servers to filter out suspicious traffic or mask the actual visitor's IP address.

On the other hand, when Computer B's ISP IP (`61.85.102.11`) is shown as the same as the `HTTP_X_FORWARDED_FOR` and `REMOTE_ADDR` values, it suggests that the request might not be coming from a suspicious or malicious source. In this case, Cloudflare might decide to bypass proxying and allow the traffic to pass through directly.

**When will Cloudflare use proxy or not use proxy?**

Cloudflare uses proxies in the following situations:

1. **Suspicious IP addresses**: If an incoming request comes from an IP address known to be associated with malicious activity.
2. **Botnet detection**: When Cloudflare detects signs of a botnet, such as rapid-fire requests or unusual traffic patterns.
3. **DDoS protection**: During DDoS attacks, Cloudflare may use proxies to filter out legitimate traffic and protect your website.

Cloudflare might not use proxy in the following situations:

1. **Trusted IP addresses**: If an incoming request comes from a trusted IP address that has been whitelisted by Cloudflare.
2. **Direct connections**: When using a direct connection (e.g., `curl -D` or `wget`) that doesn't involve a proxy.
3. **HTTP/HTTPS traffic**: For HTTPS requests, Cloudflare may use SSL/TLS certificates to encrypt the communication and bypass proxying.

**Is using a proxy a sign of a bot or malicious IP?**

Using a proxy can be a sign of a suspicious IP address, but it's not always a definitive indicator. Here are some possible scenarios:

1. **Legitimate proxy usage**: Users might use proxies for legitimate reasons, such as accessing geographically restricted content or improving security.
2. **Proxying by botnets**: Botnets might use proxies to mask their IP addresses and avoid detection.
3. **Cloudflare's proxying behavior**: As mentioned earlier, Cloudflare may use proxies to filter out suspicious traffic or mask the actual visitor's IP address.

To determine whether a proxy is being used for legitimate or malicious purposes, you can:

1. Check the `HTTP_X_FORWARDED_FOR` and `REMOTE_ADDR` values in your PHP code.
2. Inspect the request headers using tools like Chrome DevTools or Fiddler.
3. Analyze Cloudflare's logs to see if there are any suspicious traffic patterns.

Keep in mind that proxying is a common practice in web development, and not all proxies are malicious. It's essential to understand your specific use case and analyze your data accordingly.