The host name data base file, HOSTS.NET.SYS,
associates internet addresses with official host names and aliases.
This allows a user to refer to a host by a symbolic name instead
of an internet address.
When using the name server, this file serves only as a backup
when the server is not running. In this circumstance, it is a common
practice that HOSTS.NET.SYS contains
a few addresses of machines on the local network.
To create the hosts file, perform the following steps:
Copy the sample file, HOSTSAMP.NET.SYS,
to HOSTS.NET.SYS.
Modify HOSTS.NET.SYS
using any ASCII editor so that it contains information about the
nodes on your network.
To modify an already existing HOSTS.NET.SYS
file, simply use your editor to update and save the existing file.
Enter a single line for each host, including the following
information:
[internet address] [local host name] [aliases]]
A line cannot start with a space. Items are separated by any
number of blanks and/or tab characters. A pound sign (#) indicates
the beginning of a comment.
Network addresses are specified in dot format, with leading
zeros omitted and a period between each grouping. (See example addresses
in Figure 2-2 “Sample Hosts Configuration File”.)
Host names can contain any printable character other than
a white space, newline, or comment character.
 |
 |  |
 |
 | NOTE: It is very important that you omit the leading zeros
in the network addresses. If you enter the leading zeros here, the
domain name resolver will interpret the numbers as octal numbers. |
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 |  |
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Note that the IP addresses and host names used in this figure
are for purposes of example only.