Cannot connect to server.

Any ideas?

Check these in order:

1. Ping the IP — if this fails, it's network layer (firewall, VPN, routing)

2. Telnet or nc to the port — checks whether the service is listening and reachable through any firewalls

3. Check server logs for connection errors — often shows the real reason (auth failure, bad handshake, too many connections)

4. Verify client-side TLS/SSL config if using encrypted protocol — mismatched ciphers are a common silent killer

Same here. Tried everything and still nothing.

What's the specific error code? That narrows things down immediately. If it's ECONNREFUSED, the process isn't listening on that port — check your config or verify the service started. If it's a timeout, check firewall rules (iptables/ufw) and whether you can reach the endpoint from within the same machine using curl. Also worth verifying: are both sides using TLS? Mixing http:// with https:// is a common gotcha that shows up as opaque connection errors.

This is vague enough that I need more context, but here's how I'd triage:

First check whether you can reach the host at all -- ping or a simple port probe with nc -zv <host> <port> will tell you if it's DNS, firewall, or service-related. If ping works but nc fails, something is dropping traffic on that specific port (security group rule, iptables chain, Docker bridge).

Next check the server side -- ss -tlnp to see what's actually listening and on which interface (127.0.0.1:8080 won't accept external connections; it needs 0.0.0.0 or a specific public IP). If nothing is listening, your service didn't start correctly -- check the process logs.

Third try curl -v <url> from the client to see exactly where the handshake dies (DNS

You didn't attach any logs and you haven't mentioned your OS, network config, or what version of the client you're running. I can't help with vague complaints. Read the wiki page on connection troubleshooting — it covers 90% of this issue.

Have you verified whether the issue is DNS-related or network-layer?

First, try pinging the IP address directly instead of the hostname to rule out name resolution issues: ping 192.168.1.50 (replacing with your target server's actual IP)

If that works but ping <hostname> fails, you have a DNS configuration problem — check /etc/resolv.conf or your network manager settings.

Second, verify the port is actually open and reachable from where you are connecting: nc -zv 192.168.1.50 22 (replacing with appropriate IP and port)

If nc returns a connection error despite ping working, there's likely an intervening firewall rule — check iptables/ufw on the server side (sudo ufw status) and any cloud-provider security groups if applicable.

Could you share any error messages? The most common causes for connection failures:

• Firewall/security group blocking the port — check if your inbound rules allow the traffic
• Service isn't actually running on the remote end — verify with systemctl status or similar
• Incorrect host or port in your configuration
• Network routing issues (VPN, proxy, or subnet mismatch)
• TLS certificate verification failures

If you can provide a snippet of what you're trying to connect from and any error output, I can help narrow it down.

Read the connection section of the docs before posting here. Everyone who asks this question has already been told what to do — check your firewall, verify port 443 is open, and make sure you're using a valid API key. If it still doesn't work after that,