TCP/IP has become for more and more installations the preferred network
protocol, also pushed by the explosive growth of the Internet, which is
based on TCP/IP.
When using a network with only Windows95 and WindowsNT4 based systems,
you will have to assigned the IP-addresses manually (Windows98 includes an
IP-Auto-Configuration system), but more and more server-systems offer the
automatic assignment of IP-addresses via:
DHCP (Dynamic Host Configuration Protocol)
Commercial Message:
The installation of the DHCP-server on Windows NT4 server (the DHCP-server
is NOT included in Windows NT4 workstation ) is very simple:
 | In the Network-configuration, tab: Services, click on “Add“ and then select: “Microsoft DHCP Server“ |
The following notice will be displayed:
The system running the DHCP-server (distributing IP-addresses to other systems)
itself MUST use a static IP-address (manually assigned) , it can NOT request
to receive an IP-address from any DHCP-server (itself or another DHCP server).
Like after all changes to the network configuration, you have to reboot:
Configuration of the DHCP-server
 | Although the DHCP-server is listed as a Networking service, it is NOT configured from the Network applet (the Properties button is grayed out) |
 | The “DHCP – Manager” has been added to the menu for the “Administrative Tools” |
 | You need to define now a range of IP-addresses to be distributed. This range is called: “Scope“. To be able to define Scope, click first on the entry “Local Machine” to expand the entry, the “+” -sign needs to change to the “-“-sign. |
 | Only then you are able to select from the menu: “Scope” the option “Create“ |
You assign the range of IP-addresses to be assigned by DHCP-server
( in the example: all IP-addresses between 102.54.107.1 and 192.54.107.49):
usually, an IP-address is NOT assigned permanently, but only for a limited
time, called the “Lease Duration”.
On selected the “OK”-button, you will be asked on whether to activate
the scope, select “Yes”:
 | The yellow light-bulb indicates, that the scope is now active and that the DHCP-server is ready to assign the IP-addresses. |
 | To display the IP-range (“Scope”) for viewing/editing, select from the menu “Scope” the option “Properties” |
Setting up a connected Windows systems to use the DHCP-server is very simple:
 | In the Network-configuration, select the properties for the TCP/IP-protocol and just make sure, that it defines to “obtain an IP address automatically” |
To verify the assigned IP-address on a Windows95/98 system, run the
“WINIPCFG” program (usually from the RUN-menu)(On Windows NT, use IPCONFIG):
In this example, DHCP assigned the IP-address 192.54.107.1.
But there is no “Default gateway” defined !
TCP/IP requires more than just the IP-address, for communication outside
the local network-cable (the local “subnet”), it needs to know the IP-address
of the Gateway (also called Router).
DHCP can be configured to provide also this information to the clients:
 | make sure, that your Scope is selected (highlighted in blue), then select from the menu: “DHCP Options”, then “Scope” |
 | From the list of “Unused Options”, select “Router”, then use the “Add”-button. |
 | Once the “Router” is an “Active Option”, click on the button “Value” to define the IP-address for the Router. |
 | On the expanded Windows, click on “Edit Array”, allowing then to enter the IP-address of the Router, then select the “Add”-button to get the new values displayed in the list of IP-addresses. Press “OK” to exit this window. |
 | The IP-address of the Router is displayed. Press “OK” to close the DHCP-Options window. |
 | The DHCP-Mananger is now displayed for the scope also the option for the Router. |
When now checking on Windows95/98 with WINIPCFG:
the IP-address for the “Default Gateway” is defined.
If your configuration requires the use of WINS, it can be also configured
as an option of the DHCP-server.
DHCP can also be used to assigned IP-addresses for incoming RAS-
connections:
 | To view the list of IP-address already assigned, select from the menu: “Scope” the option “Active Leases” |
 | In this example, 192.54.107.1 is assign to a LAN user, while 192.54.107.2 is assigned to the Modem to handle incoming RAS TCP/IP-connections. |
