1.\" $NetBSD: ifconfig.if.5,v 1.20 2020/04/17 13:36:48 kim Exp $ 2.\" 3.\" Copyright (c) 1996 Matthew R. Green 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 20.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 21.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 22.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 23.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.Dd April 15, 2020 28.Dt IFCONFIG.IF 5 29.Os 30.Sh NAME 31.Nm ifconfig.if 32.Nd interface-specific configuration files or variables 33.Sh DESCRIPTION 34The 35.Nm 36files or variables contain information regarding the configuration 37of each network interface. 38.Nm 39is processed by 40.Pa /etc/rc.d/network 41at system boot time. 42.Pp 43For each interface 44.Pq Ar nnX 45that is to be configured, there should be either an 46.Sy ifconfig_nnX 47variable in 48.Xr rc.conf 5 , 49or an 50.Pa /etc/ifconfig.nnX 51file 52(such as the 53.Sy ifconfig_fxp0 54variable or the 55.Pa /etc/ifconfig.fxp0 56file for the 57.Sy fxp0 58interface). 59Only characters allowed in 60.Xr sh 1 61variables names should be used for 62.Ar nnX 63.Po Xr ascii 7 64uppercase and lowercase letters, digits, and underscore 65.Pc . 66.Pp 67The variable or file will get evaluated only if the interface exists on 68the system. 69Multiple lines can be placed in a variable or file, and will be 70evaluated sequentially. 71In the case of a variable, semicolons may be used instead of 72newlines, as described in 73.Xr rc.conf 5 . 74.Ao backslash Ac Ns Ao newline Ac 75sequences in files are ignored, so long logical lines may be 76made up of several shorter physical lines. 77.Pp 78Normally, a line will be evaluated as command line arguments to 79.Xr ifconfig 8 . 80.Dq Li ifconfig Ar nnX 81will be prepended on evaluation. 82Arguments with embedded shell metacharacters should be quoted in 83.Xr sh 1 84style. 85.Pp 86If the line is equal to 87.Dq dhcp , 88.Xr dhcpcd 8 89will be started for the interface. 90However, it is instead recommended that 91.Sy dhcpcd 92is set to true in 93.Xr rc.conf 5 94and any per interface configuration or restriction is done in 95.Xr dhcpcd.conf 5 . 96.Pp 97If the line is equal to 98.Dq rtsol , 99kernel processing of router advertisements will be enabled and an IPv6 100router solicitation message will be sent out on the interface. 101This is useful on networks where default routes can best be learned 102from router advertisements. 103However, if 104.Sy dhcpcd 105has been set to true in 106.Xr rc.conf 5 , 107it is assumed that 108.Xr dhcpcd 8 109will take care of sending any necessary router solicitation messages and 110processing received router advertisements through its configuration in 111.Xr dhcpcd.conf 5 112instead. 113.Pp 114If a line is empty, or starts with 115.Sq # , 116the line will be ignored as comment. 117.Pp 118If a line starts with 119.Sq \&! , 120the rest of line will get evaluated as shell script fragment. 121Shell variables declared in 122.Pa /etc/rc.d/network 123are accessible but may not be modified. 124The most useful variable is 125.Li $int , 126as it will be bound to the interface being configured with the file. 127.Pp 128For example, the following illustrates static interface configuration: 129.Bd -literal -offset indent 130# IPv4, with an alias 131inet 10.0.1.12 netmask 255.255.255.0 media 100baseTX 132inet 10.0.1.13 netmask 255.255.255.255 alias 133# let us have IPv6 address on this interface 134inet6 2001:db8::1 prefixlen 64 alias 135# have subnet router anycast address too 136inet6 2001:db8:: prefixlen 64 alias anycast 137.Ed 138.Pp 139For networks that do not use a virtual address for the default gateway 140that could be set using a single address in 141.Sy defaultroute6 , 142static IPv6 address configuration could use the 143.Dq rtsol 144keyword instead to solicit router advertisements for learning a default 145route and even achieving route redundancy given multiple responding 146routers: 147.Bd -literal -offset indent 148inet6 2001:db8::100 prefixlen 64 alias 149rtsol 150.Ed 151.Pp 152The following example sets a network name for a wireless interface 153(using quotes to protect special characters in the name), 154and starts 155.Xr dhcpcd 8 : 156.Bd -literal -offset indent 157ssid 'my network' 158dhcp 159.Ed 160.Pp 161The following example is for dynamically-created pseudo interfaces like 162.Xr gif 4 . 163Earlier versions of 164.Pa /etc/rc.d/network 165required an explicit 166.Sq create 167command for such interfaces, 168but creation is now handled automatically. 169.Bd -literal -offset indent 170up 171# configure IPv6 default route toward the interface 172!route add -inet6 default ::1 173!route change -inet6 default -ifp $int 174.Ed 175.Sh FILES 176.Pa /etc/rc.d/network 177.Sh SEE ALSO 178.Xr rc.conf 5 , 179.Xr ifconfig 8 180