good DHCPd readings

http://www.cyberciti.biz/faq/howto-ubuntu-debian-squeeze-dhcp-server-setup-tutorial/
http://www.yolinux.com/TUTORIALS/DHCP-Server.html
http://www.linuxquestions.org/questions/linux-networking-3/linux-gateway-and-dhcp-50691/

How do I configure iptables to allow access to the DHCP server?

Edit your iptables scripts and add the following lines

 
## Make sure you use an appropriate network block,  ##
## and network mask, representing the machines on your ## 
## network which should operate as clients of the dhcp serve. ##
## Syntax: ##
## /sbin/iptables -A INPUT -s net/mask -i $LAN_IFACE -p udp --dport 67:68 --sport 67:68 -j ACCEPT ##
## Adjust rules as per your setup ##
 
/sbin/iptables -A INPUT -s 192.168.1.0/24 -i eth0 -p tcp --sport 68 --dport 67 -j ACCEPT
/sbin/iptables -A INPUT -s 192.168.1.0/24 -i eth0 -p udp --sport 68 --dport 67 -j ACCEPT
 

A slightly different configuration for an internal subnet

The following is a special subnet that allows to pxe network booting using tftpd server at 192.168.0.5 (please note that you need to install and configure tftpd server separately):

 
subnet 192.168.0.0 netmask 255.255.255.0 {
  range 192.168.0.20 192.168.0.50;
  ## openbsd pxe boot file ##
  filename "openbsd/pxeboot";
 
  ## Debian 6 pxe boot file ##
  ## filename "debian6/pxelinux.0";
 
  ## Freebsd pxe boot file ##
  ## filename "freebsd/pxeboot";
 
  ## our boot server ##
  next-server 192.168.0.5; 
  option subnet-mask 255.255.255.0;
  option broadcast-address 192.168.0.255;
  option routers 192.168.0.5;
}
 

How do I add BOOTP support?

Each BOOTP client must be explicitly declared in the dhcpd.conf file.

 
## bootp my headless home router ##
host router {
     hardware ethernet 08:00:2b:4c:59:23;
     fixed-address 192.168.0.21;
     filename "debian6/pxelinux.0";
}