====ISC dhcp3-server with LDAP backend====
For large networks it might be a good idea to store DHCP-information in a central LDAP-database. Brian Masney has written a patch that gives the ISC DHCP-server an LDAP backend. You can find more information and download the patch at http://www.newwave.net/~masneyb/.

Download the sources of the ISC DHCP-server at http://www.isc.org, apply the LDAP-patch and then configure and compile the software or, even better, create binary packages for your GNU/Linux distribution of choice.

We built new Debian-packages (i386 platform only) based on the Debian Sarge source packages for the ISC DHCP-server.

Install the patched packages
  dpkg -i dhcp3-common_3.0.4-1ldap_i386.deb dhcp3-server_3.0.4-1ldap_i386.deb

Add the interface to bind to to /etc/default/dhcp3-server

Install an LDAP-enabling /etc/dhcp3/dhcpd.conf
  ldap-server                 "xenfds.intra.example.com";
  ldap-port                   389;
  # We do an anonymous bind
  # ldap-username             "cn=directorymanagerloginname";
  # ldap-password             "mypassword";
  ldap-base-dn                "ou=DHCP,dc=intra,dc=example,dc=com";
  ldap-method                 static;
  ldap-debug-file             "/var/log/dhcp-ldap-startup.log";

In the chapter on installing the Fedora Directory Server we already described the custom LDAP-scheme that is required for DHCP usage ([[64ldapdhcp.ldif]]).

A basic example to fill the DHCP part of the LDAP-server is needed to get things going. You can save it eg. as /opt/dhcp-ldap.ldif
  dn: ou=DHCP,dc=intra,dc=example,dc=com
  ou: DHCP
  objectClass: top
  objectClass: organizationalUnit
  description: DHCP Servers
  
  dn: cn=DHCP Config, ou=DHCP,dc=intra,dc=example,dc=com
  cn: DHCP Config
  objectClass: top
  objectClass: dhcpService
  dhcpPrimaryDN: cn=xendns, ou=DHCP,dc=intra,dc=example,dc=com
  dhcpStatements: ddns-update-style none
  dhcpStatements: get-lease-hostnames true
  dhcpStatements: use-host-decl-names true
  
  dn: cn=192.168.1.0, cn=DHCP Config, ou=DHCP,dc=intra,dc=example,dc=com
  cn: 192.168.1.0
  objectClass: top
  objectClass: dhcpSubnet
  objectClass: dhcpOptions
  dhcpNetMask: 24
  dhcpRange: 192.168.1.150 192.168.1.200
  dhcpStatements: default-lease-time 600
  dhcpStatements: max-lease-time 7200
  dhcpOption: netbios-name-servers 192.168.1.16
  dhcpOption: subnet-mask 255.255.255.0
  dhcpOption: routers 192.168.1.1
  dhcpOption: domain-name-servers 192.168.1.11
  dhcpOption: domain-name "intra.example.com"
  
  dn: cn=xendns, ou=DHCP,dc=intra,dc=example,dc=com
  cn: xendns
  objectClass: top
  objectClass: dhcpServer
  dhcpServiceDN: cn=DHCP Config, ou=DHCP,dc=intra,dc=example,dc=com
  
  dn: cn=xenclient, cn=DHCP Config, ou=DHCP,dc=intra,dc=example,dc=com
  cn: xenclient
  objectClass: top
  objectClass: dhcpHost
  dhcpHWAddress: ethernet 00:16:3e:3d:eb:87
  dhcpStatements: fixed-address 192.168.1.111

You can add the LDIF to the LDAP-database like so:
  /opt/fedora-ds/slapd-xenfds/ldif2ldap "cn=Directory Manager" yourpassword /opt/dhcp-ldap.ldif


As an alternative you might use the available perl-script to convert your current dhcpd.conf to LDIF.

Finally start your DHCP-server and you're done.
In case any debugging is needed, start with the files /var/log/dhcp-ldap-startup.log and /var/log/daemon.log, however Brian's patch and the ISC server do have additional options.

====ISC dhcp3-server without LDAP backend====
Below is an example of dhcpd.conf that enables running a dhcp3-server without LDAP backend.

Remember, our project doesn't support DDNS (yet).

Install the software
  apt-get install dhcp3-server

Content of /etc/dhcp3/dhcpd.conf
  allow booting;
  allow bootp;
  ddns-update-style none;
  option domain-name "intra.example.com";
  option domain-name-servers 192.168.1.11, 192.168.1.31;
  option netbios-name-servers 192.168.1.16;
  option subnet-mask 255.255.255.0;
  option broadcast-address 192.168.1.255;
  option routers 192.168.1.1;
  default-lease-time 6000;
  max-lease-time 72000;
  subnet 192.168.1.0 netmask 255.255.255.0 {
   range 192.168.1.150 192.168.1.200;
  }

In case of more than one NIC or when using a Xen domU als vehicle for your server, edit /etc/default/dhcp3-server
  INTERFACES="eth1"

Start the DHCP-server
  /etc/init.d/dhcp3-server start