hostname.if —
interface-specific configuration files
The
hostname.* files contain information regarding
the configuration of each network interface. One file should exist for each
interface that is to be configured, such as
hostname.fxp0 or
hostname.bridge0. A configuration file is not
needed for lo0.
The configuration information is expressed in a line-by-line packed format which
makes the most common cases simpler; those dense formats are described below.
Any lines not matching these packed formats are passed directly to
ifconfig(8). The
packed formats are converted using a somewhat inflexible parser and the
administrator should not expect magic — if in doubt study
ifconfig(8) and
the per-driver manual pages to see what arguments are permitted.
Arguments containing either whitespace or single quote characters must be double
quoted. For example:
inet 10.0.0.1 255.255.255.0 10.0.0.255 description "Bob's uplink"
Each line is processed separately and in order. For example:
nwid mynwid
wpakey mywpakey
dhcp
would run ifconfig to set the nwid of the interface, run it again to set the
wpakey of the interface, and then start
dhclient(8).
The following packed formats are valid for configuring network interfaces with
static addresses:
Regular IPv4 network setup:
inet
[
alias]
addr netmask
broadcast_addr
options
dest dest_addr
Regular IPv6 network setup:
inet6
[
alias]
addr
prefixlen
options
dest dest_addr
Other network setup:
addr_family
options
A typical file contains only one line, but more extensive files are possible,
for example:
inet 10.0.1.12 255.255.255.0 10.0.1.255 media 100baseTX description Uplink
inet alias 10.0.1.13 255.255.255.255 10.0.1.13
inet alias 10.0.1.14 255.255.255.255 NONE
inet alias 10.0.1.15 255.255.255.255
inet alias 10.0.1.16 0xffffffff
# This is an example comment line.
inet6 alias fec0::1 64
inet6 alias fec0::2 64 anycast
!route add 65.65.65.65 10.0.1.13
up
The above formats have the following field values:
-
-
- addr_family
- The address family of the interface, generally
“inet” or “inet6”.
-
-
alias- The literal string “alias” if this is an
additional network address for the interface.
-
-
- addr
- The optional address that belongs to the interface, such as
190.191.192.1 or fe80:2::1. It is also feasible to use a hostname as
specified in /etc/hosts. It is recommended
that an address be used instead of symbolic information, since the latter
might activate
resolver(3)
library routines.
If no address is specified, the netmask,
broadcast_addr,
dest, and
dest_addr options are invalid and will be
ignored.
-
-
- netmask
- The optional network mask for the interface, e.g.,
255.255.255.0. If addr is specified but
netmask is not, the classful mask based
on addr is used.
-
-
- broadcast_addr
- The optional broadcast address for the interface, e.g.,
190.191.192.255. The word “NONE” can also be specified in
order to configure the broadcast address based on the
netmask. The
netmask option must be present in order
to use this option.
-
-
- options
- Miscellaneous options to set on the interface, e.g.,
“media 100baseTX mediaopt full-duplex”. Valid options for a
particular interface type can be found in
ifconfig(8).
When used, the netmask and
broadcast_addr options must also be
present.
-
-
dest- If the interface needs a destination address set, this is
the literal text “dest”. As shown in the example, this
declaration should start on a separate line.
-
-
- dest_addr
- The destination address to be set on the interface, such as
190.191.192.2. It is also feasible to use a hostname as specified in
/etc/hosts. It is recommended that an address
be used instead of symbolic information which might activate
resolver(3)
library routines.
-
-
- prefixlen
- The prefixlen number, or number of bits in the netmask, to
be set on the interface, such as 64.
-
-
#- Comments are allowed. Anything following a comment
character is treated as a comment.
-
-
!command- Arbitrary shell commands can be executed using this
directive, as long as they are available in the single-user environment
(for instance, /bin or
/sbin). Useful for doing interface-specific
configuration such as setting up custom routes using
route(8) or
establishing tunnels using
ifconfig(8).
It is worth noting that “\$if” in a command line will be
replaced by the interface name.
The following packed formats are valid for configuring network interfaces with
dynamic addresses:
A DHCP-configured network interface setup consists of
dhcp
options
The above format has the following field values:
-
-
dhcp- The literal string “dhcp” if the interface is
to be configured using DHCP. See
dhclient(8)
and
dhclient.conf(5)
for more details.
-
-
- options
- Miscellaneous options to set on the interface, e.g.,
“media 100baseTX mediaopt full-duplex”. Valid options for a
particular interface type can be found in
ifconfig(8).
IPv6 stateless address autoconfiguration:
inet6
autoconf options
The above format has the following field values:
-
-
inet6- The address family.
-
-
autoconf- The literal string “autoconf”, to configure
the interface using IPv6 stateless address autoconfiguration (SLAAC).
-
-
- options
- Miscellaneous options to set on the interface, e.g.,
“media 100baseTX mediaopt full-duplex”. Valid options for a
particular interface type can be found in
ifconfig(8).
If the network interface is a bridge, the options described in the bridge
section of the
ifconfig(8) manual
page apply.
For example:
add fxp0
add ep1
-learn fxp0
#
!ipsecctl -F
#
static fxp0 8:0:20:1e:2f:2b
up # and finally enable it
-
-
- /etc/hostname.XXX
- Interface-specific configuration files.
hosts(5),
dhclient(8),
ifconfig(8),
netstart(8),
rc(8)
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