1. Connection Refused:
Occurs when the server actively rejects a connection request.
Cause: The service might not be running or configured properly.
Solution: Verify the service status and configuration files.
2. Connection Timed Out:
Indicates that the connection attempt took too long to complete
Cause: Firewall settings, network congestion, or unresponsive server.
Solution: Check firewall rules, network configurations, and server responsiveness.
3. No Route to Host:
Indicates the inability to reach the destination host.
Cause: Incorrect routing table or network misconfiguration.
Solution: Check routing tables using route or ip route commands.
4. Host Unreachable:
Similar to "No Route to Host," signifies the inability to reach the destination.
Cause: Network misconfiguration or incorrect IP address.
Solution: Verify IP configuration and network settings.
5. Destination Host Unreachable:
Indicates that the destination host is unreachable.
Cause: Network misconfiguration, incorrect IP address, or server down.
Solution: Check destination host's status and network settings
6. Network is Unreachable:
Suggests that the network is unreachable.
Cause: Network interface down or misconfigured
Solution: Check network interface status (ifconfig or ip addr) and configurations.
7. Name or Service not known:
Occurs when the hostname cannot be resolved to an IP address.
Cause: DNS resolution failure or incorrect hostname.
Solution: Verify DNS settings (/etc/resolv.conf) and hostname configuration.
8. Socket Operation on Non-Socket:
Indicates an attempt to perform a socket operation on a file or directory.
Cause: Incorrect file type used in a socket operation.
Solution: Check the file type and ensure it's a socket.
9. Permission Denied:
Occurs when the user doesn't have the necessary permissions.
Cause: Insufficient permissions to access network resources.
Solution: Adjust permissions using chmod or chown commands.
10. Socket Bind Failed:
Indicates failure to bind a socket to an address and port.
Cause: Another process may be using the same port, or insufficient privileges.
Solution: Choose a different port or ensure proper permissions.