HOSTS(SFF) UNIX System V
Name
hosts - list of hosts on network
Description
The file /etc/hosts is a list of hosts that share the
network, including the local host. It is referred to by
programs that need to translate between host names and DARPA
Internet addresses when the name server is not being used
[See named(ADMN).] Each line in the file describes a single
host on the network and consists of three fields separated
by any number of blanks or tabs:
address name aliases ...
where
address is the DARPA Internet address. Unless
another type of address is required by
some host on the network, address should
be a Class A address, which takes the
form net.node, where net is the network
number from /etc/networks (see networks
(4)), that must between 0 and 127; and
node is a value which must be unique for
each host and be between 0 and 16777215.
name is the official name of the host. If the
host is a computer system running UNIX,
it must claim this host name by executing
hostname(TC) when it is initializing
itself.
aliases... is a list of alternate names for the
host. Aliases can be used in network
commands in place of the official name.
It is suggested that you specify the hostname and the node
name [see hostname(TC) and uname(C)] as aliases for one
another for each machine listed in the /etc/hosts file.
The routines which search this file ignore comments
(portions of lines beginning with #) and blank lines.
An internet address can actually take one of four forms:
A A is a simple 32-bit integer.
A.B A is an eight-bit quantity occupying the
high-order byte and B is a 24-bit quantity
occupying the remaining bytes. This form is
suitable for a Class A address of the form
net.node.
A.B.C A is an eight-bit quantity occupying the
high-order byte; B is an eight-bit quantity
occupying the next byte; and C is a 16-bit
quantity occupying the remaining bytes. This
form is suitable for a Class B address of the
form 128.net.node.
A.B.C.D The four parts each occupy a byte in the
address.
Example
# Engineering network
192.35.53.1 laizy.Lachman.COM laizy
192.35.53.2 laidback.Lachman.COM laidback
192.35.53.85 laiter.Lachman.COM laiter# Sun-3/50 [stevea]
Files
/etc/hosts
See Also
hostname(TC), uname(C), networks(SFF), inet(ADMP).
(printed 8/17/89) HOSTS(SFF)