Why am I getting a 522 error on my website hosted on Cloudflare

If you have hosted your website on Cloudflare CDN then you or your visitor may have experienced the following problem on their browser.

Cloudflare 522 Error
Cloudflare 522 Error

A 522 error happens when a TCP connection to the web server could not be established. To initiate a TCP connection the Cloudflare edge server sends out 3 SYN packets and awaits a SYN-ACK packet in return, if it doesn’t receive one within 15 seconds the connection attempt will fail.

Common reasons for Cloudflare to not receive the SYN-ACK in return:

  1. Our connection attempt was blocked by a firewall/security plugin at the host
  2. Packets are being dropped within the host’s network
  3. The origin server was too overloaded to respond
  4. There was an issue with an upstream provider along the path

The most common solutions to the above problems are

  1. You should whitelist CloudFlare IP ranges to ensure this doesn’t happen. You can check this page on Cloudflare for the list of IP addresses.
  2. Check and lower load of the server if it is too high

Hope the above helped.

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