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HOSTS(5)		    Debian GNU/Linux manual		      HOSTS(5)

       hosts - The static table	lookup for host	names


       This manual page	describes the format of	the /etc/hosts file. This file
       is a simple text	file that associates IP	addresses with hostnames,  one
       line per	IP address. For	each host a single line	should be present with
       the following information:

	      IP_address canonical_hostname aliases

       Fields of the entry are separated by any	number of  blanks  and/or  tab
       characters.  Text  from	a "#" character	until the end of the line is a
       comment,	and is ignored.	 Host  names  may  contain  only  alphanumeric
       characters, minus signs ("-"), and periods (".").  They must begin with
       an  alphabetic  character  and  end  with  an  alphanumeric  character.
       Aliases	provide	 for  name changes, alternate spellings, shorter host-
       names, or generic hostnames (for	example, localhost).   The  format  of
       the host	table is described in RFC 952.

       The Berkeley Internet Name Domain (BIND)	Server implements the Internet
       name server for UNIX systems. It	augments or  replaces  the  /etc/hosts
       file  or	 host name lookup, and frees a host from relying on /etc/hosts
       being up	to date	and complete.

       In modern systems, even though the host table has  been	superseded  by
       DNS, it is still	widely used for:

	      Most systems have	a small	host table containing the name and ad-
	      dress information	for important hosts on the local network. This
	      is  useful  when	DNS  is	not running, for example during	system

       NIS    Sites that use NIS use the host table as input to	the  NIS  host
	      database.	 Even  though NIS can be used with DNS,	most NIS sites
	      still use	the host table with an entry for all local hosts as  a

       isolated	nodes
	      Very small sites that are	isolated from the network use the host
	      table instead of DNS. If the local information  rarely  changes,
	      and  the	network	 is  not connected to the Internet, DNS	offers
	      little advantage.

EXAMPLE	localhost  foo  bar      master

       Before the advent of DNS, the host table	was the	only way of  resolving
       hostnames on the	fledgling Internet. Indeed, this file could be created
       from the	official host data base	maintained at the Network  Information
       Control Center (NIC), though local changes were often required to bring
       it up to	date regarding unofficial aliases and/or unknown  hosts.   The
       NIC  no	longer maintains the hosts.txt files, though looking around at
       the time	of writing (circa 2000), there are historical hosts.txt	 files
       on the WWW. I just found	three, from 92,	94, and	95.


       hostname(1)  resolver(3), resolver(5), hosts(5),	hostname(7), named(8),
       Internet	RFC 952

       This manual page	was written by Manoj Srivastava	<>,
       for the Debian GNU/Linux	system.

Debian				  2002-06-16			      HOSTS(5)


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