Which file should be edited to configure network interfaces in modern Linux systems?

In modern Linux systems, especially in distributions like Ubuntu starting from version 17.10, network configuration has transitioned to using Netplan. This involves editing configuration files that are typically located in the /etc/netplan/ directory, with a .yaml extension (hence the '*.yaml' in the option).

Netplan uses YAML syntax for defining network interfaces and allows the specification of network settings in a clear and structured way. After editing these files, the user applies the configuration using the 'netplan apply' command. This modern approach streamlines network management and provides a more user-friendly method for configuring complex network setups, thus making it the preferred method in contemporary Linux distributions.

Other files mentioned serve different purposes and are not used for configuring network interfaces in the same way. For example, /etc/network/interfaces is mainly associated with older Debian-based systems that used ifupdown, while /etc/hosts is used for hostname resolution, and /etc/resolv.conf manages DNS resolution configuration. Therefore, for modern Linux systems using Netplan, editing the YAML files in /etc/netplan/ is the correct approach to configure network interfaces.