Question 2: Why is my site coming from California?!

Customer Inquiry

Subject: Why is my site coming from California?!

I’m in London, but looking at your IPs it shows that you are serving my website from California. Can that be right? Why is that? I thought you were supposed to serve my website from some places close to me?

Response to Customer

Hello,

Thank you for contacting Cloudflare Support.

That's an excellent question, and I can clarify why you might be seeing a California IP address even though you are in London.

Cloudflare operates a global network of data centers, and we use a technique called Anycast to route visitors to the nearest data center.

This means that the same IP address is announced from all of our locations.

When you use an IP geolocation tool, it will often show the location where the IP address was originally registered (in this case, California), not necessarily the location where the traffic is being served from.

So, while the IP address may be registered in California, you are most likely being served from our London data center, as you are located in London. The traffic is not actually crossing the Atlantic.

You can verify this by looking at the "colo" field in the `cf-ray` response header. For example, if you see `CF-RAY: 123456789-LHR`, the "LHR" indicates that your request was served from our London data center (Heathrow).

I hope this clears things up. Please let me know if you have any other questions.

Best regards,

João Estêvão
Customer Support Engineer
Cloudflare

Thought Process

1. Understand the Customer's Confusion:
   
   • The customer's confusion is understandable. They see a California IP and assume their traffic is going there. My primary goal is to educate them about Anycast and how IP geolocation can be misleading.


2. Explain Anycast Simply:
   
   • I need to explain a complex technical concept (Anycast) in a simple, non-technical way. The key is to emphasize that the *same IP* is in *many places at once*, and they are routed to the closest one.

Tools I Would Use

cURL or Browser DevTools:

• I would use `curl -I example.com` or the developer tools in a browser to inspect the response headers of the customer's website.
• The key piece of information is the `CF-RAY` header, which contains the data center code (e.g., LHR for London, SFO for San Francisco). This would be the primary way to confirm where the traffic is being served from.

Cloudflare's IP Ranges:

• I would refer to Cloudflare's public IP ranges page to confirm that the IP the customer is seeing is indeed a Cloudflare IP. While the customer stated it was, it's always good to verify.

IP Geolocation Tools:

• I would use a tool like MaxMind to show the customer that these tools often report the registration location of an IP block, not the serving location. This would help to reinforce my explanation of Anycast.