NAME

dns-dhcp - generate dhcp tables from DNS tables

SYNOPSIS

dns-dhcp [ option... ][ infile [ outfile ]]
dns-dhcp -Help
dns-dhcp -VERSion

DESCRIPTION

The dns-dhcp program is used to generate portions of the /etc/dhcp.conf file from the forward DNS tables, augmented with ``ether a'' entries.

This is supplemented with an additional ``dhcp'' class, so that extra information may be defined.

The output format is described in the dhcpd (8) manual entry. Usually, the output of the dns-dhcp command is included into the /etc/dhcp.conf file, rather then define the entire file with the output in the dns-dhcp command.

DHCP TYPES

The ``dhcp'' class has the following defined types:

filename: The absolute path of the bootfile.

THE * DEFAULT

The special host name ``*'' may be used to specify defaults. These may be over-riden by specific entries. The most recently see default of each type name is remembered. This may be exploited, for example, to set different servers and gateways for different networks.

OPTIONS

The following options are understood:

-Help: Provide some help with using the dns-dhcp program.
-VERSion: Print the version of the dns-dhcp program being executed.

All other options will produce a diagnostic error.

See the file man1/arglex.so.

See the file man1/exit.so.

EXAMPLE

The idea is that you have all of the information concerning each computer in the one file. This makes it less likely that something will be omitted, and simpler to change if the name or IP address changes.

Given a database file called ``example.com'' and which contains the following text


See the file man1/example.so.

You can generate the /etc/dhcp.conf file using the following command

% dns-dhcp example.com /etc/dhcp.conf
%

Here is what you would see as the output


See the file man1/example.dhcp.so.

Note that the output uses relative names.

Makefile

All of this can be automated using the following makefile fragment:

/etc/dhcp.conf: example.com
        dns-dhcp example.com $@

By doing this, all you need to do is edit the example.com file, and the use the make(1) command to bring everything up-to-date.

If you were using NIS, NIS+ or LDAP you would update them, rather than the static file.

See the file man1/copyright.so.

See the file man1/author.so.