net-tools

The net-tools package delivers critical utilities for managing Linux network interfaces, ARP cache, routing tables, and related hardware configurations. It supports tasks such as displaying and modifying ARP entries, configuring interfaces, viewing network statistics, and handling IP tunnels or multicast addresses. These tools are fundamental for network troubleshooting, configuration, and diagnostics in Linux environments.

Use cases include inspecting network connections with netstat, setting up static ARP mappings with arp, configuring interfaces via ifconfig, and managing routing tables with route. Additional specialized tools like mii-tool for media interface status, iptunnel for IP tunnels, and slattach for serial line attachments cater to specific hardware and advanced IP configurations. Note that hostname utilities are provided in a separate package.

While some modern tools like ip and ss have superseded net-tools components, they remain widely used for compatibility and specific legacy requirements.

Net-tools interacts directly with the Linux kernel's network subsystem via system calls and ioctls to query and manipulate configurations. Tools like arp modify the kernel ARP cache, ifconfig uses SIOCGIF* ioctls for interface settings, netstat reads /proc/net files and socket statistics, and route manipulates the kernel forwarding information base (FIB). Hardware-specific utilities like mii-tool access MII registers over network drivers, while iptunnel creates virtual tunnel devices using kernel GRE/IPIP modules.