Block All Connections from Multi Countries on Ubuntu Firewall

Safeguard your Ubuntu VPS from unauthorized access by blocking all incoming connections from China and Hong Kong using the powerful iptables firewall.

Prerequisites:

• Ubuntu VPS with root or sudo privileges
• Basic understanding of iptables commands

Steps:

1. Identify Country Codes: Determine the two-letter country codes for China (CN) and Hong Kong (HK).
2. Block Connections: Use the iptables command to block incoming connections from the specified countries:

   sudo iptables -I INPUT -s cn -j DROP
   sudo iptables -I INPUT -s hk -j DROP

3. Verify Block: Check the iptables rules to confirm the block:

   sudo iptables -L

Example:

Blocking connections from China and Hong Kong:

   sudo iptables -I INPUT -s cn -j DROP
   sudo iptables -I INPUT -s hk -j DROP

Explanation:

• sudo iptables: Invokes the iptables firewall tool with root privileges.
• -I INPUT: Inserts a rule into the INPUT chain, which controls incoming traffic.
• -s cn: Specifies the source country code (CN for China).
• -j DROP: Instructs iptables to drop packets matching the specified criteria.

Benefits of Blocking:

• Enhanced Security: Protects your VPS from potential cyberattacks originating from these regions.
• Reduced Risk: Mitigates the threat of unauthorized access and data breaches.
• Improved Control: Maintains control over incoming traffic to your server.

Additional Considerations:

• Whitelist Specific IPs: If necessary, whitelist trusted IP addresses from China or Hong Kong to allow legitimate connections.
• Regularly Review Rules: Periodically review and update iptables rules to adapt to changing security threats.
• Alternative Methods: Consider using geoIP modules or advanced firewall configurations for more granular control.

By implementing these iptables rules, you can effectively block all incoming connections from China and Hong Kong, safeguarding your Ubuntu VPS from unauthorized access and enhancing its overall security posture.