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Screenshot of ipconfig /all output in Windows XP

In computing, ipconfig (internet protocol configuration) in Microsoft Windows is a console application that displays all current TCP/IP network configuration values and can modify Dynamic Host Configuration Protocol DHCP and Domain Name System DNS settings.[1]

In most cases, the ipconfig command is used with the command-line switch /all. This results in more detailed information than ipconfig alone.

Forced release and renew[edit]

An important additional feature of ipconfig is to allow system admins to force refreshing of the DHCP IP address of the host computer to request a different IP address. This is done using two commands in sequence. First, ipconfig /release is executed to force the client to immediately give up its lease by sending the server a DHCP release notification which updates the server's status information and marks the old client's IP address as "Available". Then, the command ipconfig /renew is executed to request a new IP address.[2][3] Where a computer is connected to a cable or DSL modem, it may have to be plugged directly into the modem network port to bypass the router, before using ipconfig /release and turning off the power for a period of time, to ensure that the old IP address is taken by another computer.[4]

There are situations where the /release and /renew commands are not sufficient. The /flushdns command can be used to clear the Domain Name System (DNS) cache so that the connection is reset [5]

For ISP's that don't allow a user to request a new IP address using ipconfig /release and /renew, a good alternative is to use a DD-WRT hardware router setup with a VPN service. With this setup it's possible to get a new VPN IP address simply by cycling the power on the router.

Mac OS X ipconfig[edit]

ipconfig in Mac OS X serves as a wrapper to the IPConfiguration agent, and can be used to control the BootP and DHCP client from the command line interface.[6] Like most UNIX-based operating systems, Mac OS X also uses ifconfig for more direct control over network interfaces, such as configuring static IP addresses.

See also[edit]


External links[edit]