Http code 523 error

What is the name of the domain?

chuma.cc

What is the error number?

523

What is the error message?

Origin Unreachable

What is the issue you’re encountering

randomly got 523 error

What steps have you taken to resolve the issue?

1.stop fail2ban
2.clear all the banned ips

What feature, service or problem is this related to?

I don’t know

What are the steps to reproduce the issue?

We are currently using Cloudflare’s Free plan along with your SSL service for our website. Recently, we have been encountering the following issues:

Intermittent HTTP 523 errors appearing on certain pages.

When the homepage encounters a 523 error, other image resources also fail to load.

Interestingly, if we append a random query string (e.g., ?t=2) to the image URLs, they load successfully — which leads us to suspect a caching-related issue.

Here’s what we have attempted so far:

Cleared the cache

Verified our origin server is stable and SSL is correctly configured

Checked for potential blocks from firewalls or Fail2Ban against Cloudflare IPs

Despite these efforts, the root cause remains unclear. We would appreciate it if Cloudflare could help us:

Investigate whether any Cloudflare nodes or connections are experiencing issues

Confirm if any cache corruption or retrieval errors are occurring

Provide further troubleshooting suggestions

Thank you for your support. We’re happy to provide any additional information you may need.