Which IP-address did we get ?

by Johannes Helmig [Published on 9 May 2002 / Last Updated on 9 May 2002]

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


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.

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 !


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


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

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 )
- .....
- ......


"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.

The Author — Johannes Helmig

Dr.Johannes Helmig is working as Director, Technical Knowledge Management in the Belgium office of Gerber Technology where he is involved in Customer Service and internal training, with special interest in Networking.

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