inet_type - default Internet protocol type
/etc/default/inet_type
The inet_type file defines the default IP protocol to use. Currently this file is only used by the ifconfig(1M) and netstat(1M) commands.
The inet_type file can contain a number of <variable>=<value> lines. Currently, the only variable defined is DEFAULT_IP, which can be assigned a value of IP_VERSION4, IP_VERSION6, or BOTH.
The output displayed by the ifconfig and netstat commands can be controlled by the value of DEFAULT_IP set in inet_type file. By default, both commands display the IPv4 and IPv6 information available on the system. The user can choose to suppress display of IPv6 information by setting the value of DEFAULT_IP. The following shows the possible values for DEFAULT_IP and the resulting ifconfig and netstat output that will be displayed:
Displays only IPv4 related information. The output displayed is backward compatible with older versions of the ifconfig(1M) and netstat(1M) commands.
Displays both IPv4 and IPv6 related information for ifconfig and netstat.
Displays both IPv4 and IPv6 related information for ifconfig and netstat.
The command-line options to the ifconfig and netstat commands override the effect of DEFAULT_IP as set in the inet_type file. For example, even if the value of DEFAULT_IP is IP_VERSION4, the command
example% ifconfig -a6
will display all IPv6 interfaces.
This is what the inet_type file must contain if you want to suppress IPv6 related output:
DEFAULT_IP=IP_VERSION4