Trilight Zone

[digital8]

If your TCP/IP Properties have been configured to :
"obtain an IP address automatically":



For your TCP/IP network to work, you must get an IP-address :
Without an IP-address, your network will not work !

There are different systems acting as DHCP-server :
- a network server (like : Windows NT4/2000 server configured with DHCP-server )
- hardware routers
- software routers ( Microsoft Internet Connection Sharing ICS host or 3rd Party solutions )
- IP-Auto-Configuration as integrated with Windows98/ME/2000/XP :
an IP-address is generated from the range 169.254.x.y (where the x.y is generated randomly),subnet-mask : 255.255.0.0


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If you are using/intend to use "obtain an IP address automatically", please do NOT reply
on it without verifying, that you did get an IP-address assigned.

Please, verify, that you got a valid IP-address :

if you got :

0.0.0.0 -> you did not get any IP-address !
169.254.x.x. -> your system could not locate a DHCP server and used the Auto-IP-Configuration
if you are trying to connect to a server, this is then an indicator that you have a
problem connecting to the server, you should check the cabling.

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To check the IP-address, use on the Start-menu the RUN-command to execute "winipcfg"
(on Windows95/98/ME, on Windows XP, check the status, or on Windows NT4/2000/XP, use : "ipconfig" ) :


Select from the drop-down your network adapter :

(often, the PPP-Adapter for the Internet connection via
modem is the first selection in the list).

Verify, that values are listed for IP-address and
Subnet Mask.
If the IP-address and Subnet Mask are listed with
"0.0.0.0", then there is NO IP-address assigned
(no DHCP-server on the network and/or the
IP-Auto-Configuration did not work )
and without an IP-address, TCP/IP networking
does NOT work !

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Like NT4 and Windows2000, you can open a
Command-Prompt windows and type : ipconfig

Or in the "Network Connections" view for the
network connection the "Status" :
- right-click your connection and select from the
Context / Popup menu : Status


select the tab : "Support"
where you will find the information:
- the IP-address, subnet mask and Gateway information
- was the IP-address assigned manually, via DHCP, automatic

example for an IP-address assigned by a DHCP-server :

- address Type : Assigned by DHCP

Most DHCP-server assign more than just the IP-address,
Subnet-mask and gateway address.
Click on the button "Details" to get all information displayed.
window "Network Configuration Details":

- Physical Address ( MAC-address )
- IP-address and Subnet-mask
- Default Gateway
- DHCP-server
- DNS Server


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On Windows NT4, Windows 2000
and Windows XP, open a Command
Prompt window and type : ipconfig



If your IP-address is shows as
0.0.0.0, then you have not (yet?)
received an IP-address.
On Windows 2000/XP, it may
take up to a minute after a reboot,
until an IP-address is assigned via
Auto-IP-Configuration.

example : No IP-address (yet) assigned
Windows IP Configuration
Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
IP Address. . . . . . . . . . . . . . . :
Subnet Mask . . . . . . . . . . . . . .:
Default Gateway . . . . . . . . . . . . :
0.0.0.0
0.0.0.0


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if the IP-address is not defined
manually and if no DHCP-server
is found, then Windows98/ME
and Windows 2000/XP will
assign an IP-address via
Auto-IP-Configuration


example : IP-address assigned via Auto-IP-Configuration :
Windows IP Configuration
Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
Autoconfiguration IP Address.. . . :
Subnet Mask . . . . . . . . . . . . . .:
Default Gateway . . . . . . . . . . . . :
169.254.4.69
255.255.0.0

There is no special indication,
when an IP-address was
assigned by a DHCP-server.

example : IP-address assigned via DHCP-server :
Windows IP Configuration
Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
IP Address... . . . . . . . . . . . . . . :
Subnet Mask . . . . . . . . . . . . . .:
Default Gateway . . . . . . . . . . . . :
192.168.1.100
255.255.255.0
192.168.1.10

Much more information is displayed , when typing : "ipconfig /all" :

It will list :
- Physical address (MAC-address)
- IP-address and subnet mask
- default Gateway
- DHCP-server and Lease information (obtained and when it will expire )
- .....
- ......


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"ipconfig" can do much more than display the TCP/IP settings.

Like with all Microsoft command-line utilities, you can display help by "ipconfig /? " :


"ipconfig" can also be used to release an IP-address and/or to Renew an IP-address :
request a new IP-address from a DHCP-server.