iptables and nftables IP Blocking

Linux iptables and its successor nftables provide powerful, low-level network filtering with excellent performance.

Basic iptables Blocking

Use iptables DROP or REJECT rules to block individual IPs or ranges.

Using ipset

ipset enables efficient matching against large IP lists with minimal performance overhead.

Modern nftables

nftables provides improved syntax and performance for modern Linux systems.

Best Practices

• Use ipset - Hash-based sets for large blocklists.
• Persist Rules - Save rules to survive reboots.
• Logging - Log blocked packets for analysis.