What modern tools or technologies have replaced iptables for managing network security in Linux?

Modern tools that are replacing iptables for network security management in Linux include:

• nftables — the official replacement for iptables, more modern and efficient, with improved syntax and performance. It allows managing packet filtering, NAT, and other functions.

• firewalld — a daemon that uses nftables or iptables under the hood but provides a convenient interface for dynamic rule management through zones and services.

• Cilium — a solution for network security and observability in Kubernetes, using eBPF for high-performance traffic filtering and control.

• Calico — a network plugin for Kubernetes with security policy capabilities, which can also operate based on iptables or eBPF.

Thus, nftables is a direct successor to iptables, while firewalld and eBPF-based solutions (Cilium) offer more modern and flexible approaches to network security management in Linux.