HOSTS

NAME

SYNOPSIS

DESCRIPTION

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. Optional aliases provide for name changes, alternate spellings, shorter hostnames, or generic hostnames (for example, localhost).

The Berkeley Internet Name Domain (BIND) Server implements the Internet name server for Unix systems. It augments or replaces the /etc/hosts file or hostname 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In modern systems, even though the host table has been superseded by DNS, it is still widely used for:

bootstrapping

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

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 backup.

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.

FILES

NOTES

Historical Notes

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.  

EXAMPLE

127.0.0.1       localhost
192.168.1.10    foo.mydomain.org       foo
192.168.1.13    bar.mydomain.org       bar
146.82.138.7    master.debian.org      master
209.237.226.90  www.opensource.org

SEE ALSO

COLOPHON

Index

NAME

SYNOPSIS

DESCRIPTION

FILES

NOTES

Historical Notes

EXAMPLE

SEE ALSO

COLOPHON