520 Error on subdomain

Website, Application, Performance
1

Thanks in advance for your help!

I’m running a personal domain (no site) and use subdomains to point to devices in my home network.

I have been using Cloudflare and assigning subdomain DNS records to point to my public IP address, which then connects through a reverse proxy administered by my Load Balancer and redirects each sub to a device on my network.

What currently has been working is my QNAP NAS, Proxmox Server, Load Balancer (hosted on my Proxmox), Host Router and AP Router. All work perfectly.

Today I configured a Music Server as a Docker Container on my NAS and gave it a static IP address and port on my LAN then setup Cloudflare as usual. The server works great locally but I can’t access it through the subdomain without getting the 520 Error: SSL_ERROR_RX_RECORD_TOO_LONG.

Reading through the docs on CF this error is typically: “SSL received a record that exceeded the maximum permissible length.” This generally indicates that the remote peer system has a flawed implementation of SSL, and is violating the SSL specification.

I’m wondering if this is a Docker Issue, NAS Issue or other and if there is any work around besides setting this up again and hosting it on my Proxmox server?

Thanks in advance (again).

2

Does the issue persist if you pause Cloudflare on the zone or set the DNS record to unproxied :grey:?

3

I unproxied the DNS record and the error remains.

Using a different browser I am told that the subdomaining is sending no data.

4

That indicates the issue is with your setup rather than Cloudflare. Just make sure you cleared DNS cache after unproxying :grey: the DNS record.

Non-Cloudflare issues are generally out-of-scope of this forum, but I can take a quick look if you share the domain.

1 Like
5

How can I share without publicly posting on this forum?

And thank you!