.\" $NetBSD: ifconfig.if.5,v 1.22 2020/10/11 22:46:24 kim Exp $ .\" .\" Copyright (c) 1996 Matthew R. Green .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, .\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED .\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, .\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .Dd October 12, 2020 .Dt IFCONFIG.IF 5 .Os .Sh NAME .Nm ifconfig.if .Nd interface-specific configuration files or variables .Sh DESCRIPTION The .Nm files or variables contain information regarding the configuration of each network interface. .Nm is processed by .Pa /etc/rc.d/network at system boot time. .Pp For each interface .Pq Ar nnX that is to be configured, there should be either an .Sy ifconfig_nnX variable in .Xr rc.conf 5 , or an .Pa /etc/ifconfig.nnX file (such as the .Sy ifconfig_fxp0 variable or the .Pa /etc/ifconfig.fxp0 file for the .Sy fxp0 interface). Only characters allowed in .Xr sh 1 variables names should be used for .Ar nnX .Po Xr ascii 7 uppercase and lowercase letters, digits, and underscore .Pc . .Pp The variable or file will get evaluated only if the interface exists on the system. Multiple lines can be placed in a variable or file, and will be evaluated sequentially. In the case of a variable, semicolons may be used instead of newlines, as described in .Xr rc.conf 5 . .Ao backslash Ac Ns Ao newline Ac sequences in files are ignored, so long logical lines may be made up of several shorter physical lines. .Pp Normally, a line will be evaluated as command line arguments to .Xr ifconfig 8 . .Dq Li ifconfig Ar nnX will be prepended on evaluation. Arguments with embedded shell metacharacters should be quoted in .Xr sh 1 style. .Pp If the line is equal to .Dq dhcp , .Xr dhcpcd 8 will be started for the interface. However, it is instead recommended that .Sy dhcpcd is set to true in .Xr rc.conf 5 and any per interface configuration or restriction is done in .Xr dhcpcd.conf 5 . .Pp If the line is equal to .Dq rtsol , a dedicated .Xr dhcpcd 8 process will be started for processing received router advertisements and sending out IPv6 router solicitation messages on the interface. This is useful on networks where default routes can best be learned from router advertisements. However, if .Sy dhcpcd has been set to true in .Xr rc.conf 5 , it is assumed that that .Xr dhcpcd 8 process will take care of sending any necessary router solicitation messages and processing received router advertisements on all interfaces, and therefore no per-interface process is started. .Pp If a line is empty, or starts with .Sq # , the line will be ignored as comment. .Pp If a line starts with .Sq \&! , the rest of line will get evaluated as shell script fragment. Shell variables declared in .Pa /etc/rc.d/network are accessible but may not be modified. The most useful variable is .Li $int , as it will be bound to the interface being configured with the file. .Pp For example, the following illustrates static interface configuration: .Bd -literal -offset indent # 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 .Ed .Pp For networks that do not use a virtual address for the default gateway that could be set using a single address in .Sy defaultroute6 , static IPv6 address configuration could use the .Dq rtsol keyword instead to solicit router advertisements for learning a default route and even achieving route redundancy given multiple responding routers: .Bd -literal -offset indent inet6 2001:db8::100 prefixlen 64 alias rtsol .Ed .Pp The following example sets a network name for a wireless interface (using quotes to protect special characters in the name), and starts .Xr dhcpcd 8 : .Bd -literal -offset indent ssid 'my network' dhcp .Ed .Pp The following example is for dynamically-created pseudo interfaces like .Xr gif 4 . Earlier versions of .Pa /etc/rc.d/network required an explicit .Sq create command for such interfaces, but creation is now handled automatically. .Bd -literal -offset indent up # configure IPv6 default route toward the interface !route add -inet6 default ::1 !route change -inet6 default -ifp $int .Ed .Sh FILES .Pa /etc/rc.d/network .Sh SEE ALSO .Xr rc.conf 5 , .Xr ifconfig 8