1*33da33a4Suwe.\" $NetBSD: hosts.5,v 1.14 2021/03/12 10:00:32 uwe Exp $ 2b5930afcSjtc.\" 3b5930afcSjtc.\" Copyright (c) 1983, 1991, 1993 4b5930afcSjtc.\" The Regents of the University of California. All rights reserved. 561f28255Scgd.\" 661f28255Scgd.\" Redistribution and use in source and binary forms, with or without 761f28255Scgd.\" modification, are permitted provided that the following conditions 861f28255Scgd.\" are met: 961f28255Scgd.\" 1. Redistributions of source code must retain the above copyright 1061f28255Scgd.\" notice, this list of conditions and the following disclaimer. 1161f28255Scgd.\" 2. Redistributions in binary form must reproduce the above copyright 1261f28255Scgd.\" notice, this list of conditions and the following disclaimer in the 1361f28255Scgd.\" documentation and/or other materials provided with the distribution. 14075022b3Sagc.\" 3. Neither the name of the University nor the names of its contributors 1561f28255Scgd.\" may be used to endorse or promote products derived from this software 1661f28255Scgd.\" without specific prior written permission. 1761f28255Scgd.\" 1861f28255Scgd.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 1961f28255Scgd.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2061f28255Scgd.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2161f28255Scgd.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2261f28255Scgd.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2361f28255Scgd.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2461f28255Scgd.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2561f28255Scgd.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2661f28255Scgd.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2761f28255Scgd.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2861f28255Scgd.\" SUCH DAMAGE. 2961f28255Scgd.\" 30b5930afcSjtc.\" @(#)hosts.5 8.2 (Berkeley) 12/11/93 3161f28255Scgd.\" 32ff1595ffSlukem.Dd November 17, 2000 3361f28255Scgd.Dt HOSTS 5 347a1aea16Sgarbled.Os 3561f28255Scgd.Sh NAME 3661f28255Scgd.Nm hosts 3761f28255Scgd.Nd host name data base 3861f28255Scgd.Sh DESCRIPTION 3961f28255ScgdThe 4061f28255Scgd.Nm hosts 412baa698aSlukemfile contains information regarding the known hosts on the network. 42abda4debSlukemIt can be used in conjunction with the DNS, and the 43abda4debSlukem.Tn NIS 44abda4debSlukemmaps 45abda4debSlukem.Sq hosts.byaddr , 46abda4debSlukemand 47abda4debSlukem.Sq hosts.byname , 48abda4debSlukemas controlled by 49abda4debSlukem.Xr nsswitch.conf 5 . 50abda4debSlukem.Pp 5161f28255ScgdFor each host a single line should be present 5261f28255Scgdwith the following information: 532baa698aSlukem.Dl address hostname [alias ...] 542baa698aSlukem.Pp 552baa698aSlukemThese are: 562baa698aSlukem.Bl -tag -width hostname -compact -offset indent 57ff1595ffSlukem.It Em address 5861f28255ScgdInternet address 59ff1595ffSlukem.It Em hostname 609572fc31SderaadtOfficial host name 61ff1595ffSlukem.It Em alias 622baa698aSlukemAlias host name 632baa698aSlukem.El 6461f28255Scgd.Pp 6561f28255ScgdItems are separated by any number of blanks and/or 6671e62d7dSlukemtab characters. A hash sign 6771e62d7dSlukem.Pq Dq \&# 6871e62d7dSlukemindicates the beginning of 6961f28255Scgda comment; characters up to the end of the line are 7061f28255Scgdnot interpreted by routines which search the file. 7161f28255Scgd.Pp 7261f28255ScgdWhen using the name server 7361f28255Scgd.Xr named 8 , 74abda4debSlukemor 75abda4debSlukem.Xr ypserv 8 , 7661f28255Scgdthis file provides a backup when the name server 7761f28255Scgdis not running. 7861f28255ScgdFor the name server, it is suggested that only a few addresses 7961f28255Scgdbe included in this file. 8061f28255ScgdThese include address for the local interfaces that 8161f28255Scgd.Xr ifconfig 8 8261f28255Scgdneeds at boot time and a few machines on the local network. 8361f28255Scgd.Pp 84b08666e2SitojunAs network addresses, both IPv4 and IPv6 addresses are allowed. 8571e62d7dSlukemIPv4 addresses are specified in the conventional dot 8671e62d7dSlukem.Pq Dq \&. 8771e62d7dSlukemnotation using the 88b08666e2Sitojun.Xr inet_pton 3 8961f28255Scgdroutine 9061f28255Scgdfrom the Internet address manipulation library, 9161f28255Scgd.Xr inet 3 . 92b08666e2SitojunIPv6 addresses are specified in the standard hex-and-colon notation. 9361f28255ScgdHost names may contain any printable 9461f28255Scgdcharacter other than a field delimiter, newline, 9561f28255Scgdor comment character. 9661f28255Scgd.Sh FILES 9761f28255Scgd.Bl -tag -width /etc/hosts -compact 9861f28255Scgd.It Pa /etc/hosts 9961f28255ScgdThe 10061f28255Scgd.Nm hosts 10161f28255Scgdfile resides in 10261f28255Scgd.Pa /etc . 10361f28255Scgd.El 10461f28255Scgd.Sh SEE ALSO 10561f28255Scgd.Xr gethostbyname 3 , 106abda4debSlukem.Xr nsswitch.conf 5 , 10761f28255Scgd.Xr ifconfig 8 , 10861f28255Scgd.Xr named 8 10961f28255Scgd.Rs 11061f28255Scgd.%T "Name Server Operations Guide for BIND" 11161f28255Scgd.Re 11261f28255Scgd.Sh HISTORY 11361f28255ScgdThe 11461f28255Scgd.Nm 11561f28255Scgdfile format appeared in 11661f28255Scgd.Bx 4.2 . 117