Bring a network interface up or down
Syntax ifup [options] -a | IFACE... ifdown [options] -a|IFACE... Options -a, --all If given to ifup, affect all interfaces marked auto. Interfaces are brought up in the order in which they are defined in /etc/network/interfaces. If given to ifdown, affect all defined interfaces. Interfaces are brought down in the order in which they are currently listed in the state file. Only interfaces defined in /etc/network/interfaces will be brought down. --force Force configuration or deconfiguration of the interface. --allow=CLASS Only allow interfaces listed in an allow-CLASS line in /etc/network/interfaces to be acted upon. -i FILE --interfaces=FILE Read interface definitions from FILE instead of from /etc/network/interfaces. -n, --no-act Don't configure any interfaces or run any "up" or "down" commands. --no-mappings Don't run any mappings. See interfaces for more information about the mapping feature. -v, --verbose Show commands as they are executed. -h, --help Display help for ifup -V, --version Show copyright and version information.
Bring up all the interfaces defined with auto in /etc/network/interfaces :
Bring up interface eth0:
Bring down all interfaces that are currently up:
"Either I'm dead or my watch has stopped" ~ Groucho Marx's last words
ifplugd - A link detection daemon for ethernet devices.
logout - Exit a login shell.