=head1 NAME

B<makedhcp> - Creates and updates DHCP configuration files.

=head1 SYNOPSIS

B<makedhcp> B<-n> [B<-l>|B<--localonly>]

B<makedhcp> B<-a> [B<-l>|B<--localonly>]

B<makedhcp> B<-a -d> [B<-l>|B<--localonly>]

B<makedhcp> B<-d> I<noderange> [B<-l>|B<--localonly>]

B<makedhcp> I<noderange> [B<-s> I<statements>] [B<-l>|B<--localonly>]

B<makedhcp> [I<-h|--help>]

=head1 DESCRIPTION

The B<makedhcp> command creates and updates the DHCP configuration on the management node and service nodes. 
The B<makedhcp> command is supported for both Linux and AIX clusters.

=over 3

=item 1.

Start by filling out the L<networks(5)|networks.5> table properly.

=item 2.

Then use the B<makedhcp -n> option to create a new dhcp configuration file.
You can set the site table, dhcplease attribute to the lease time for the dhcp client. The default value is 43200. 

=item 3.

Next, get the node IP addresses and MACs defined in the xCAT database.
Also, get the hostnames and IP addresses pushed to /etc/hosts (using L<makehosts(8)|makehosts.8>) and to DNS (using L<makedns(8)|makedns.8>).

=item 4.

Then run B<makedhcp> with a noderange or the B<-a> option.  This will inject into dhcpd configuration data pertinent to the specified nodes.
On linux, the configuration information immediately takes effect without a restart of DHCP.

=back

If you need to delete node entries from the DHCP configuration, use the B<-d> flag.  

=head1 OPTIONS

=over 12

=item B<-n>

Create a new dhcp configuration file with a network statement for each network the dhcp daemon should listen on.
(Which networks dhcpd should listen on can be controlled by the dhcpinterfaces attribute in the L<site(5)|site.5> table.)
The B<makedhcp> command will automatically restart the dhcp daemon after this operation.
This option will replace any existing configuration file (making a backup of it first).
For Linux systems the file will include network entries as well as certain general parameters such as a dynamic range and omapi configuration.
For AIX systems the file will include network entries.
On AIX systems, if there are any non-xCAT entries in the existing configuration file they will be preserved and added to the end of the new configuration file.

=item B<-a>

Define all nodes to the DHCP server.  (Will only add nodes that can be reached, network-wise, by this DHCP server.)
The dhcp daemon does not have to be restarted after this.
On AIX systems B<makedhcp> will not add entries for cluster nodes that will be installed using NIM.  The entries for these nodes will be managed by NIM.

=item I<noderange>

Add the specified nodes to the DHCP server configuration.

=item B<-s> I<statements>

For the input noderange, the argument will be interpreted like dhcp configuration file text.

=item B<-d> I<noderange>

Delete node entries from the DHCP server configuration. On AIX, any entries created by NIM will not be removed.

=item B<-a -d>

Delete all node entries, that were added by xCAT, from the DHCP server configuration.

=item B<-l>|B<--localonly>

Configure dhcpd on the local machine only.  Without this option, makedhcp will also send this
operation to any service nodes that service the nodes in the noderange.

=item B<-h|--help>

Display usage message.

=back

=head1 RETURN VALUE

0 The command completed successfully.

1 An error has occurred.

=head1 EXAMPLES

=over 3

=item 1.

Create a new DHCP configuration file and add the network definitions:

 makedhcp -n

=item 2.

Define all nodes to the dhcp server:

 makedhcp -a

Note:  This does not add nodes that will be installed with AIX/NIM.

=item 3.

Will cause dhcp on the next request to set root-path appropriately for only node5.  Note some characters (e.g. ") must be doubly escaped (once for the shell, and once for the OMAPI layer).

 makedhcp node5 -s 'option root-path  \"172.16.0.1:/install/freebsd6.2/x86_64\";'

=back

=head1 FILES

DHCP configuration files:

[AIX]     /etc/dhcpsd.cnf

[SLES]    /etc/dhcpd.conf

[RH]      /etc/dhcp/dhcpd.conf

=head1 SEE ALSO

L<noderange(3)|noderange.3>