My site keeps going down Error 521

Hi, I was using xampp for my server but whenever i reload my site, it gets me a 521 error.
Now i’m using IIS because i thought that was the real problem, but i keep getting this error.
I noticed that my site is online, but only when i reload the page in the computer where the server is hosted, so when i enter to my page from any other devices (laptop, mobile, tablet), my site is only visible for a few seconds, then i get Error 521.

What would be the issue? I hope you can help me soon because i have no idea what’s happening.

Thank you.

Hi @ysvandres,

A 521 error happens when Cloudflare is unable to make a TCP connection to your origin server. Review the suggestions in this Community Tip for Quick Fix Ideas.

Thank you for your reply, @domjh

I already tried that, but i had no success.

Have you made sure to whitelist the IP addresses IP Ranges on the server?

I think i did it, but could you help me out with that please? In case i did something wrong.

It depends what your server is running, but your hosting provider should be able to offer some assistance (unless you host your own server?).

I’m hosting my server in my laptop for now.

Ok, I’m afraid I can’t help then, I know a reasonable amount about Cloudflare, but not enough about servers to be of any use!

Hopefully one of the other MVPs or Regulars can help… @sandro?

Ehm, how would that work at all? Is your laptop accessible from the Internet and has a static public IP address?

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Well @sandro , i was using XAMPP and some time ago people could access to my site but idk what happened.

Well, then lets start with what the domain is :wink:

How familiar are you with server administration?

My domain is, i got it from bluehost.

I’m a little new at this, I mean, i just do this as a hobbie and try to learn all by myself. So that’s why I have some trouble giving you more details, but i can do whatever you tell me to.

The domain is properly configured on Cloudflare, however I assume the DNS configuration is either not correct or points to an inaccessible machine. Does the IP address you configured end in 248? If so, is that the correct IP address?

No, it ends with 31.

If you dont mind posting it here, do so. Otherwise run a check for it over at and tell me when you checked it, so I can have a look at it.

Actually, your site is up →

It returns a 404 however, which comes from your server. HTTPS is a different story though.

I already checked at sitemeer and it said: “Hmm, is only partially available”

Yes, thats because of the 404 your server returns. For HTTPS, it does not seem to be configured at all.

You’ll need to fix your server configuration to return proper content and to work on HTTPS.

Well, how can I disable HTTPS? I just don’t need it for now.

Switch SSL at to “Off”.