FIX: Error message in a .NET remoting application when you use IPv6 addresses: "A socket operation was attempted to an unreachable host"


Consider the following scenario:
  • In a Microsoft .NET Framework remoting application on a computer that is running Microsoft Windows XP or Microsoft Windows Server 2003, you use IP version 6 (IPv6) site-local addresses or IPv6 link-local addresses.
  • The .NET Framework remoting application uses the TcpChannel channel.
In this scenario, you receive the following error message:
System.Net.Sockets.SocketException: A socket operation was attempted to an unreachable host


When you use IPv6 addresses on a computer that is running Windows XP or Windows Server 2003, the Microsoft .NET Framework removes the zone ID from the Uniform Resource Identifier (URI) before the remoting application connects to the server.

When you use IPv6 addresses on a computer that is running Windows Vista, the .NET Framework remoting application uses the local sub-net if the zone ID is not specified. Therefore, this problem does not occur on Windows Vista.


Hotfix information

A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that is described in this article. Apply it only to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next .NET Framework 2.0 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Customer Support Services to obtain the hotfix. For a complete list of Microsoft Customer Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Note This hotfix can be used when you use the following:
  • IPv6 site-local addresses or IPv6 link-local addresses
  • The HttpChannel channel
  • Server-activated objects
For other scenarios, follow the steps that are mentioned in the "Workaround" section.


You must have the .NET Framework 2.0 installed to apply this hotfix.

Restart Requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File Information

The English version of this hotfix 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.
File nameFile versionFile sizeDateTimePlatform


To work around this problem, use one of the following methods:
  • If you use IPv6 site-local addresses or IPv6 link-local addresses, use the HttpChannel channel instead of the TcpChannel channel.
  • If you use the TcpChannel channel, use IPv6 global addresses instead of IPv6 site-local addresses or of IPv6 link-local addresses.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

For more information about software update terminology, 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

Call stack information

Server stack trace:

at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
at System.Net.Sockets.Socket.Connect(EndPoint remoteEP)
at System.Runtime.Remoting.Channels.RemoteConnection.CreateNewSocket(EndPoint ipEndPoint)
at System.Runtime.Remoting.Channels.RemoteConnection.CreateNewSocket()
at System.Runtime.Remoting.Channels.SocketCache.GetSocket(String machinePortAndSid, Boolean openNew)
at System.Runtime.Remoting.Channels.Tcp.TcpClientTransportSink.SendRequestWithRetry(IMessage msg, ITransportHeaders requestHeaders, Stream requestStream)
at System.Runtime.Remoting.Channels.Tcp.TcpClientTransportSink.ProcessMessage(IMessage msg, ITransportHeaders requestHeaders, Stream requestStream, ITransportHeaders& responseHeaders, Stream& responseStream)
at System.Runtime.Remoting.Channels.BinaryClientFormatterSink.SyncProcessMessage(IMessage msg)

文書番号:939525 - 最終更新日: 2011/10/08 - リビジョン: 1