HOSTNAME.IF(5)            OpenBSD Programmer's Manual           HOSTNAME.IF(5)

NAME
     hostname.if and bridgename.if - interface-specific configuration files

DESCRIPTION
     The hostname.* and bridgename.* 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
     bridgename.bridge0. However, a configuration file is not needed for lo0.
     Note that multiple entries can be used per configuration file.

     The following three formats are valid for hostname.* files.

     Regular ipv4 network setup:

         addr_family [alias] addr netmask broadcast_addr options
         dest dest_addr

     Regular ipv6 network setup:

         addr_family [alias] addr prefixlen options

     Other network setup:

         addr_family options

     A typical file contains only one line, but more extensive files are pos-
     sible, for example:

         inet 10.0.1.12 255.255.255.0 10.0.1.255 media 100baseTX
         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
         inet6 alias fec0::1 64
         inet6 alias fec0::2 64 anycast
         # This is an example comment line.
         !wicontrol \$if -t 2  # Set to 2Mbps

     The above formats have the following field values:

         addr_family
                 The address family of the interface, generally ``inet'' or
                 ``inet6.''

         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 which
                 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, i.e.,
                 255.255.255.0.

         broadcast_addr
                 The optional broadcast address for the interface, i.e.,
                 190.191.192.255

         options
                 Optional miscellaneous options to set on the interface, i.e.,

                 ``media 100baseTX mediaopt full-duplex''.

         dest    If the interface needs a destination address set, this is the
                 literal text ``dest''. As shown in the example, this declara-
                 tion 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 re-
                 solver(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-line
                 Arbitrary shell commands can be executed using this direc-
                 tive.  Useful for doing interface specific configuration us-
                 ing commands like wicontrol(8), setting up custom routes us-
                 ing route(8), or establishing tunnels using ifconfig(8). It
                 is worth noting that ``\$if'' in a command line will be re-
                 placed by the interface name.

     A DHCP-configured network interface setup consists of

         dhcp options

     For example,

         dhcp media 100baseTX mediaopt full-duplex

     The above format has the following field values:

         dhcp    The literal string ``dhcp'' if the interface is to be config-
                 ured using DHCP.  See dhclient(8) and dhclient.conf(5) for
                 more details.

         options
                 Optional miscellaneous options to set on the interface, i.e.,
                 ``media 100baseTX mediaopt full-duplex''.

     IPv6 stateless address autoconfiguration:

         rtsol options

     The above format has the following field values:

         rtsol   The literal string ``rtsol'' if the interface is to be con-
                 figured using IPv6 stateless address autoconfiguration.  This
                 should be used on single interface host only, as IPv6 speci-
                 fications are silent about the behavior on multi-interface
                 case.  Also note that the kernel must be configured to accept
                 IPv6 router advertisement, and configured as host (non-
                 router).  Add the following lines into sysctl.conf(5):

                     net.inet6.ip6.forwarding=0
                     net.inet6.ip6.accept_rtadv=1

         options
                 Optional miscellaneous options to set on the interface, i.e.,
                 ``media 100baseTX mediaopt full-duplex''.

     An addressless network interface setup (useful for bridge(4) member in-
     terfaces and interfaces to be used with pppoe(8)) consists of

         up options

     The above format has the following field values:

         up      The literal string ``up'' if the interface is to be simply
                 brought up.

         options
                 Optional miscellaneous options to set on the interface, i.e.,
                 ``media 100baseTX mediaopt full-duplex''.

     The final file format only applies to bridgename.bridge* files.  A bridge
     interface setup consists of

         brconfig-arguments
         brconfig-arguments
         ...

     For example,

         add fxp0
         add ep1
         -learn fxp0
         #
         !ipsecadm flush
         #
         static fxp0 8:0:20:1e:2f:2b
         up    # and finally enable it

     The options are as follows:

         brconfig-arguments
                 brconfig(8) is called for each successive line.  Comments
                 starting with `#' and commands to be executed prefixed by `!'
                 are permitted.

SEE ALSO
     hosts(5), dhcp(8), ifconfig(8), rc(8)

OpenBSD 2.9                    September 2, 1999                             3
