Tunnel Troubleshooting
The tunnel shows Offline or Not yet installed
The connector is not running or cannot reach us. Check the service on your machine:
systemctl status cdnshark-tunnel # Linux
cdnshark-tunnel status # any platformThe connector needs outbound UDP port 51820. Some corporate and hotel networks block outbound UDP entirely; if yours does, the connector cannot currently connect — a TCP fallback is in development.
Error 523 — Origin Unreachable
The tunnel itself is healthy, but the connector could not reach the address you published. Almost always one of:
- The application is not running, or is listening on a different port.
- The Private host or IP is wrong. Remember it is resolved from the connector machine, so
127.0.0.1means that machine. - A local firewall on the origin is blocking the connection.
Test it from the connector machine itself, for example curl -I http://127.0.0.1:3000. If that fails, the problem is local and not with CDNShark.
Error 523 — Unknown tunnel
The tunnel was moved or removed while a site still pointed at it. Re-select the tunnel as the origin and save.
The site loads but shows the wrong page or a redirect loop
Your origin is probably matching on the hostname it receives. CDNShark sends your real domain in the Host header, so make sure a virtual host exists for it on your server.
It worked, then stopped after a reboot
On Linux the installer enables a systemd service, so it should restart automatically. On macOS there is no service unit yet, and on Windows the connector must be registered as a startup task — see the Windows tab on your tunnel page.