What is a DHCP server?
-----------------------

A DHCP server assigns IP addresses to client computers
every time when they request it. The computer that
participate in a network asks for it's IP address at
startup. This is very often used in enterprise networks
to reduce the configuration effort. All IP addresses of 
all computers are stored in a database that resides on
a server machine.

What is this DHCP server good for?
----------------------------------

I experienced the following situation: I have a desktop
computer and a laptop at work. Whenever I take my laptop
home I have to turn off the DHCP support and type in an
IP address and a subnet mask to communicate between my
home computer and the laptop. When I take the laptop back 
to work I have to enable the DHCP support again. This is
very annoying and time consuming, because Windows requires
a reboot after a change in the IP settings.

With this static DHCP server I can use my home computer as
a DHCP server and I can simply put the laptop on my small
IP network at home without any changes in the IP settings.


How to setup the static DHCP server?
------------------------------------

1.  Put the dhcpsrv.exe and dhcpsrv.ini file into the
    same directory somewhere on your computer.

2.  You need to know the physical address of the computers
    that are supposed to get an IP address assigned. The 
    physical address consists of 6 bytes and are given in 
    hexadecimal notation. Example: 01-02-03-04-05-06.

3a. Open the dhcpsrv.ini file and create a section for
    each client including his (unique) IP address. Example:

	[01-02-03-04-05-06]
	IPADDR=1.2.3.4

	[01-02-03-04-05-07]
	IPADDR=1.2.3.5

3b. From V1.5 on you can also let the DHCP server perform
    an auto-configuration. Instead of creating a section 

	[01-02-03-04-05-06]
	IPADDR=1.2.3.4

    you can let the DHCP server do that for you. You only
    need to add the following to your settings section:

	[Settings]
	IPPOOL_1=1.2.3.4-200

    Every unknown client will be automatically added to the
    INI file just the same way as if you had put it in there
    manually. Note that you can have as many as 10 different
    IP pools (IPPOOL_0 ... IPPOOL_9). Each pool defines ip
    addresses of the form a1.a2.a3.a4-b4. All IP addresses
    between a1.a2.a3.a4 and a1.a2.a3.b4 are part of the pool.


4.  Some settings are common for every client computer. You
    can put them into a [General] section. Everything that is
    not found in the physical address section is looked up in
    the general section. Here is a typical [General] section:

	[General]
	SUBNETMASK=255.255.255.0
	NODETYPE=8  ; Hybrid

5.  You can setup additional entries. These entries are Router,
    DNS and DOMAINNAME:

	Router
	------
	ROUTER_1=1.2.3.4
	..
	ROUTER_9=1.2.3.9

	DNS server
	----------
	DNS_1=1.2.3.10
	..
	DNS_9=1.2.3.19

	DOMAINNAME=mydomain

6.  Start the dhcpsrv.exe. If you are running Windows NT or
    Windows 2000 then the dhcpsrv will ask you whether you
    want to use it as a service or not. This is a new feature
    in the version 1.3.
    The advantage of a service is that you don't need to logon
    to start the dhcp server - it is automatically started.
    You can not use the dhcp server as a service, if you
    use Windows 9x. I recommend to put the dhcpsrv.exe into
    the autostart folder if you are not running it as a service.

7.  After you installed the dhcp server as a service you can
    use the dhcpsrv.exe itself to start or stop the service.
    Simply start it again. Otherwise you will find a little 
    icon in the lower right corner of your screen that allows
    you to stop the dhcp server.


If you have any questions or recommendations:
E-Mail me: Uwe.Ruttkamp@gmx.net
or visit my WEB page: http://ruttkamp.gmxhome.de/
