Connection Issues
Diagnose and resolve SSH connection problems
Connection Refused
Connection refused error
Possible Causes
- •SSH server not running
- •Wrong host or port
- •Blocked by firewall
Solutions
- Check if SSH service is running on server: sudo systemctl status sshd
- Verify host address and port number are correct
- Check firewall settings: sudo ufw status or sudo iptables -L
- Try from a different network
Connection Timeout
Connection timed out error
Possible Causes
- •Server offline
- •Network issues
- •Firewall dropping packets
- •Wrong IP address
Solutions
- Verify server is online (ping or web console)
- Check network connection status
- Verify VPN connection if required
- Double-check IP address is correct
💡 Tip
To increase connection timeout, adjust 'Connect Timeout' in Connection Settings > Advanced.
Host Key Verification Failed
Occurs when the host key differs from the previously stored one.
What This Error Means
SSH verifies the server's identity using a host key. If this key has changed, it could mean the server was reinstalled or a man-in-the-middle attack occurred.
Solutions
- Verify if the server was recently reinstalled
- Confirm with admin if host key was changed
- If confirmed safe, select 'Update Key' in HejShell
- If suspicious, do not connect
⚠️ Security Warning
Ignoring host key changes poses security risks. Always confirm with the server administrator.
Connection Drops
Connection frequently disconnects
Possible Causes
- •Unstable network
- •Server-side timeout settings
- •NAT/firewall timeout
- •Server overload
Solutions
- Enable Keep-alive in connection settings
- Set Keep-alive interval to 30-60 seconds
- Switch to a more stable network
- Ask server admin to set ClientAliveInterval
Slow Connection
Connection is slow or laggy
Possible Causes
- •Insufficient network bandwidth
- •Server overload
- •High network latency
- •DNS lookup delay
Solutions
- Try from a different network
- Enable compression in connection settings
- Try connecting directly with IP instead of DNS
- Ask server admin to check server status
DNS Resolution Failed
Occurs when the hostname cannot be resolved to an IP address.
Solutions
- Verify hostname spelling
- Try connecting directly with IP address
- Change DNS server (e.g., 8.8.8.8)
- Check network settings
Diagnostic Steps
Follow these steps to systematically diagnose connection issues.
- Run 'Connection Test' in Settings > Diagnostics
- Check logs (Settings > Logs)
- Test connecting to the same server with another SSH client
- If issue persists, contact support with logs attached
Still Having Issues?
If the above methods don't resolve the issue, please contact us with connection logs attached. dev@hej.ai.kr