This article describes an update package that is available for computers that are running Microsoft Windows XP with Service Pack 2 (SP2). This update upgrades Windows Peer Name Resolution Protocol (PNRP) to PNRP version 2.0. PNRP version 2.0 for Windows XP provides the same features as PNRP version 2.0 for Windows Vista.
This update enables Windows XP SP2-based programs that use PNRP to communicate with Windows Vista programs that use PNRP.
Note PNRP version 2.0 is not backward-compatible with earlier versions of PNRP. If you install this update, you cannot use programs that use the updated version of PNRP to communicate with programs that use earlier versions of PNRP. Also, Windows XP does not let applications use the getaddrinfo() Windows Sockets function to resolve PNRP names that are encoded as fully qualified domain names.
The following are known issues with PNRP resolution:
In rare occasions, PNRP resolutions yield no results even though PNRP resolutions in the link local scope appear to succeed. Therefore, when you use PNRP in Windows XP SP2, verify that a successful resolution returns actual results before your program continues. Generally, if the first PNRP name resolution returns no results, a second attempt does return results.
When one or more parameters are set incorrectly, name registration is unsuccessful. However, the name resolution may appear to succeed. You may experience this problem if one or more of the following conditions are true:
A comment field is too long
The extended payload is too big
The specified peer name is not valid
An incorrect cloud name is specified
In this scenario, the PeerPnrpRegister function may return a result of "S_OK."
A Windows Vista-based computer cannot bootstrap into a link local cloud that only consists of Windows XP machines that are running PNRP v2.0. This behavior occurs because PNRP bootstrapping uses the Simple Service Discovery Protocol (SSDP) over IPv6 in Windows Vista and IPv4 in Windows XP.
Note Windows XP-based machines are capable of bootstrapping into a link local cloud consisting of computers that are running Windows Vista.
The following file is available for download from the Microsoft Download Center:
For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.
You must have Windows XP SP2 installed. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
322389 How to obtain the latest Windows XP service pack
You must install the security update that is mentioned in Microsoft Knowledge Base article 922819. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
922819 MS06-064: Vulnerabilities in TCP/IP IPv6 could allow denial of service
You must restart the computer after you apply this update.
Update replacement information
This update does not replace any other update.
The English version of this update has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates
For more information about PNRP version 2.0 and about other networking features for Windows Vista, visit the following Microsoft Web site: