ifdown

Disable interface eth0

$ ifdown [eth0]

$ ifdown [[-a|--all]]

ifdown [options] <interface>

-h, --help
    Display help text and exit.

-v, --verbose
    Enable verbose mode; provides more detailed output.

-n, --no-act
    Don't actually execute commands; just print what would be done.

-i, --interfaces <file>
    Use specified interfaces file instead of /etc/network/interfaces.

-f, --force
    Force deconfiguration even if the interface is not managed.

-a, --all
    Bring down all interfaces defined in /etc/network/interfaces.

The ifdown command deactivates a network interface in Linux. It's typically used with configuration files in /etc/network/interfaces (on Debian-based systems) to manage network settings. The command takes the interface name as an argument. It executes scripts located in /etc/network/if-down.d/ to cleanly shut down the interface, unconfiguring IP addresses, removing routes, and stopping related services.

ifdown ensures a controlled shutdown process, preventing data loss or unexpected behavior due to abrupt disconnection. This is crucial for maintaining network stability and preventing connectivity issues. It interacts with the operating system's networking stack to properly disable the specified interface. ifdown is often used in conjunction with ifup to bring interfaces up and down as needed. Some distributions utilize NetworkManager, making ifdown less relevant for typical use cases. However, understanding ifdown remains important for system administrators managing network configurations directly.

ifdown returns 0 if it succeeds; otherwise, it returns a non-zero error code.

The primary configuration file used by ifdown is /etc/network/interfaces. This file defines the network interfaces and their configuration settings.

ifup(8), interfaces(5), ip(8)