Microsoft KB Archive/931859

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Address prefix change for the Teredo address format in Windows XP

Article ID: 931859

Article Last Modified on 2/16/2007


  • Microsoft Windows XP Professional
  • Microsoft Windows XP Home Edition


This article describes the address prefix change for the Teredo address format in Microsoft Windows XP.


Internet Assigned Numbers Authority (IANA) has allocated a new 2001:0000::/32 address prefix as part of the standardization of the Teredo address format in Request for Comments (RFC) 4380, "Teredo: Tunneling IPv6 over UDP through Network Address Translations (NATs)." The original 3ffe:831f::/32 address prefix is being deprecated. The 3ffe:831f::/32 address prefix is used in Microsoft Windows XP.

Windows XP Service Pack 2 (SP2)-based computers that are IPv6-capable hosts require the new address prefix to connect to Windows Vista-based computers over Teredo. The Teredo address prefix change is being deployed on all Windows XP SP2-based computers as part of the IPv6 security update.

The new Teredo address prefix is deployed together with the IPv6 security update as part of a broader IPv6 initiative. For more information about the IPv6 security update, visit the following Microsoft Web site:

For more information about Teredo, visit the following Microsoft Web site:

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

922482 A computer that is running Microsoft Windows XP may not recognize the new Teredo address format

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