DHCP server
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 anIP-Auto-Configuration
system), but more and more server-systems offer the
automatic assignment of IP-addresses via:
DHCP (Dynamic
Host Configuration
Protocol)
The installation of the DHCP-server on Windows NT4
server
(the DHCP-serveris 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) it self 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
configuredas 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. |
