[Bug]: [Coolify Cloud] Cloudflare Tunnel setup makes the server unreachable by Coolify

[pvillega]

Error Message and Logs

Server is reachable:
Server is not reachable. Please validate your configuration and connection.
Check this [documentation](https://coolify.io/docs/knowledge-base/server/openssh) for further help.

Error: Connection timed out during banner exchange

Hosted at: app.coolify.com

Steps to Reproduce

1. Create a new Hetzner server, using Ubuntu 24.04. Don't use any cloud-init configuration.
2. Add the server to Coolify (Cloud)
3. Once verified, enable Cloudflare Tunnel > Automatic. Provide token and domain
4. Cloudflare tunnel works. I can ssh via the browser. The tunnel reports as active. I can ssh from my laptop. Coolify Hosted can't see the server, and can't verify it.

Example Repository URL

No response

Coolify Version

v4.0.0-beta.380

Are you using Coolify Cloud?

No (self-hosted)

Operating System and Version (self-hosted)

Ubuntu 24.04

Additional Information

After installing Cloudflare Tunnel on a server managed by Coolify Cloud (not self-hosted), Coolify can't see the server any more.

After the Tunnel installation, I can access the server via the tunnel or using a direct ssh connection.
But Coolify asks me to verify the server again, and when I try, it says the server is not reachable. I can't seem to revert that status, I need to wipe the server.

I had a question in Discord about this, although I am not sure if it adds much more context: https://discord.com/channels/459365938081431553/1331359316145471568/1331359316145471568

[myLawd]

1. You may need to allow Cloudflare ips in your iptables rules. https://www.cloudflare.com/ips/
2. Also check your servers firewall rules are in place https://developers.cloudflare.com/cloudflare-one/connections/connect-networks/deploy-tunnels/tunnel-with-firewall/
3. check this tut here if you're using zero trust: https://developers.cloudflare.com/cloudflare-one/connections/connect-networks/configure-tunnels/remote-management/

[pvillega]

I found the issue. Writing it here for the future when someone hits the same problem.

The issue was a Cloudflare Access application that matched the domain. This meant there was an authentication step on the domain, even via ssh.

It was an old security that I had forgotten about. Thanks for the help, this can be closed :)