What is nftables?

nftables is a subsystem of the Linux kernel providing a framework for packet filtering and classification. It replaces the existing iptables, arptables, and ebtables tools, offering a unified syntax and improved performance for managing network filtering rules. It allows defining rules that inspect network packets based on various criteria (IP address, port, protocol, etc.) and take actions like accepting, dropping, or modifying the packet. It is commonly used for firewalls, network address translation (NAT), and traffic shaping.