Automatic Private IP Addressing
Last updated: 10/19/01
Q. What is Automatic
Private IP Addressing (APIPA)?
A. Windows 98, 98 SE, Me, and 2000 have an
Automatic Private IP Addressing (APIPA) feature that will automatically assign
an Internet Protocol address to a computer on which it installed. This
occurs when the TCP/IP protocol is installed, set to obtain it's IP address
automatically from a Dynamic Host Configuration Protocol server, and
when there is no DHCP server present or the DHCP server is not available. The Internet
Assigned Numbers Authority (IANA) has reserved private IP addresses
in the range of 169.254.0.0 -169.254.255.255 for Automatic Private
After the network adapter has been assigned an automatic
IP address, a computer can communicate with any other computers on the local
network that are also configured by APIPA or have static IP address manually
set to the 169.254.x.y (where x.y is the client's unique identifier) address
range with a subnet mask of 255.255.0.0.
You may want to turn-off this feature if...
- Your network uses routers, including broadband routers with built-in DHCP
- Your network is connected to the Internet without a NAT or proxy server.
Use Start, Run, enter winipcfg, select the adapter for Windows 98, 98 SE,
Me to detect APIPA and to release and renew the automaitc IP when a DHCP server
becomes available. The windows 2000 equivalent is ipconfig. Use
Start, Run, enter cmd and then enter ipconfig at the command prompt. Enter...
... to obtain a list of command options.
Knowledgebase Article Q220874, Automatic Windows 98/Me TCP/IP Addressing
Without a DHCP Server
for more information and how to turn-off this feature.