Title: ifconfig


Before using an IP interface, the ifconfig utility should be used.

From ifconfig(8):

"The ifconfig utility initializes a TCP/IP device setting the IP address and/or netmask."

ifconfig makes the ioctl() system call:

result= ioctl(ip_fd, NWIOSIPCONF, &ipconf)

ifconfig has the following syntax:

ifconfig [-I ip-device] [-h ipaddr] [-n netmask] [-iv]

This command:

ifconfig -I /dev/ip1 -h 20.1.1.1 -n 255.255.255.0

assigns an IP address and a netmask to the "/dev/ip1" device file.

This command:

ifconfig -h 10.1.1.1 -n 255.255.255.0

assigns an IP address and a netmask to the default IP device (/dev/ip).