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IFCONFIG.IF(5) NetBSD File Formats Manual IFCONFIG.IF(5)
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ifconfig.if -- interface-specific configuration files or variables
The ifconfig.if files or variables contain information regarding the con-
figuration of each network interface. ifconfig.if is processed by
/etc/rc.d/network at system boot time.
For each interface (nnX) that is to be configured, there should be either
an ifconfig_nnX variable in rc.conf(5), or an /etc/ifconfig.nnX file
(such as the ifconfig_fxp0 variable or the /etc/ifconfig.fxp0 file for
the fxp0 interface). The variable or file will get evaluated only if the
interface exists on the system. Multiple lines can be placed in a vari-
able or file, and will be evaluated sequentially. In the case of a vari-
able, semicolons may be used instead of newlines, as described in
Normally, a line will be evaluated as command line arguments to
ifconfig(8). ``ifconfig nnX'' will be prepended on evaluation. Argu-
ments with embedded shell metacharacters should be quoted in sh(1) style.
If the line is equal to ``dhcp'', dhcpcd(8) will be started for the
If a line is empty, or starts with `#', the line will be ignored as com-
If a line starts with `!', the rest of line will get evaluated as shell
script fragment. Shell variables declared in /etc/rc.d/network are
accessible but may not be modified. The most useful variable is $int, as
it will be bound to the interface being configured with the file.
For example, the following illustrates static interface configuration:
# IPv4, with an alias
inet 10.0.1.12 netmask 255.255.255.0 media 100baseTX
inet 10.0.1.13 netmask 255.255.255.255 alias
# let us have IPv6 address on this interface
inet6 2001:db8::1 prefixlen 64 alias
# have subnet router anycast address too
inet6 2001:db8:: prefixlen 64 alias anycast
The following illustrates dynamic configuration setup with dhclient(8)
# autoconfigure IPv4 address
# autoconfigure IPv6 address. Be sure to set $ip6mode to autohost.
The following example sets a network name for a wireless interface (using
quotes to protect special characters in the name), and starts dhcpcd(8):
ssid 'my network'
The following example is for dynamically-created pseudo interfaces like
gif(4). Earlier versions of /etc/rc.d/network required an explicit
`create' command for such interfaces, but creation is now handled auto-
# configure IPv6 default route toward the interface
!route add -inet6 default ::1
!route change -inet6 default -ifp $int
NetBSD 5.0.1 January 9, 2009 NetBSD 5.0.1