Ensure a TCP/IP interface is available
|If you are not root, specify the full path: /usr/sbin/if_up.|
if_up [-ap] [-r retries] [-s seconds] interface...
- Wait until all specified interfaces are configured. The default is to wait until a single interface is configured.
- Wait only until the specified interfaces are present. The default is to wait until the interfaces are both present and configured. This is useful if you intend to configure the interface manually, after it is present (e.g. using the ifconfig utility).
- -r retries
- The number of times to walk the interface list. The default is 5.
- -s seconds
- Wait this number of seconds before rewalking the interface list. The default is 1.
- Name of the interface to wait on (e.g. en0, en1, ...).
You can use this convenience utility while booting to ensure a TCP/IP interface is available to those utilities that require one. It's primarily intended for use with the dhcp.client. When if_up is run in the foreground in a startup script, the script doesn't continue until the specified interfaces are marked as "UP" and have been assigned an IP address, or the utility has timed out.
- The if_up utility requires the libsocket.so shared library.
- The if_up utility is located in the /usr/sbin/ directory, which is not included in the default PATH of non-root users. If you are not root, specify the full path.
- An error occurred.