ISA Server 2006 forwards requests to an incorrect Web server when a client computer accesses Web sites that have different host names in the same session

This article has been archived. It is offered "as is" and will no longer be updated.
SYMPTOMS
Consider the following scenario:
  • In Microsoft Internet Security and Acceleration (ISA) Server 2006, you create a Web farm that contains multiple Web servers.
  • You create multiple Web publishing rules to publish multiple Web sites by using the same Web farm.
  • In the Web publishing rules, the load balance mechanism is set to Cookie based.
In this scenario, ISA Server forwards requests to an incorrect Web server. When a client computer accesses Web sites that have different host names in the same session, ISA Server does not forward the request to the same Web server.
CAUSE
This problem occurs when the Web browser does not send a Web Publishing Load Balancing (WPLB) cookie to ISA Server.

By default, a Web browser does not use a cookie from one site in a request that it sends to another site. Therefore, the request that is sent to ISA Server does not contain the WPLB cookie. In this situation, ISA Server may select a different server from the Web farm to handle the request.
RESOLUTION
  1. Apply hotfix 940250. For more information about this hotfix, click the following article number to view the article in the Microsoft Knowledge Base:
    940250 Description of the ISA Server 2006 hotfix package: July 16, 2007
  2. Start Notepad, and then paste the following script into a new document.
    Const SE_VPS_GUID = "{143F5698-103B-12D4-FF34-1F34767DEabc}"Const SE_VPS_NAME = "CookieUserData"Const SE_VPS_VALUE = " domain=.site.com;"'Define the constants neededconst Error_FileNotFound = &H80070002Const fpcPolicyWebPublishing = 2Main(WScript.Arguments)Sub Main(args)    If(args.Count = 1) Then        SetWPLBcookieUserData args(0)    Else        Usage()    End IfEnd SubSub SetWPLBcookieUserData(ruleName)    ' Create the root object.    Dim root  ' The FPCLib.FPC root object    Set root = CreateObject("FPC.Root")    ' Declare the other objects needed.    Dim isaArray        ' An FPCArray object    Dim rule            ' An FPCPolicyRule object    ' Get a reference to the array object.    Set isaArray = root.GetContainingArray()    ' Get a reference to the policy rule specified.    On Error Resume Next    Set rule = isaArray.ArrayPolicy.PolicyRules.Item(ruleName)    If Err.Number = Error_FileNotFound Then        WScript.Echo "The policy rule specified could not be found."    Else        Err.Clear        On Error GoTo 0        If rule.Type = fpcPolicyWebPublishing Then            Dim VendorSets  ' An FPCVendorParametersSets collection            Dim VendorSet   ' An FPCVendorParametersSet object            Set VendorSets = rule.VendorParametersSets            On Error Resume Next            Set VendorSet = VendorSets.Item( SE_VPS_GUID )            If Err.Number <> 0 Then                Err.Clear                ' Add the item                Set VendorSet = VendorSets.Add( SE_VPS_GUID )                CheckError                WScript.Echo "New VendorSet added... " & VendorSet.Name            Else                WScript.Echo "Existing VendorSet found... value- " &  VendorSet.Value(SE_VPS_NAME)            End If            Err.Clear            VendorSet.Value(SE_VPS_NAME) = SE_VPS_VALUE            If Err.Number <> 0 Then                CheckError            End If            rule.Save            WScript.Echo "Done!"        Else            WScript.Echo "The policy rule specified is not a Web publishing rule."        End If    End IfEnd SubSub Usage()    WScript.Echo "Usage:" & VbCrLf _        & "  " & WScript.ScriptName & " RuleName" & VbCrLf _        & "" & VbCrLf _        & "    RuleName - Name of the Web publishing rule"    WScript.QuitEnd SubSub CheckError()    If Err.Number <> 0 Then        WScript.Echo "An error occurred: 0x" & Hex(Err.Number) & " " & Err.Description        Err.Clear    End IfEnd Sub
  3. In the following text, replace .site.com; with the domain name of the Web site:
    Const SE_VPS_VALUE = " domain=.site.com;"
    Note Make sure that you include the semicolon at the end of the domain name. For example, if the same publishing rule allows for traffic to the hr.contoso.com site and to the finance.contoso.com site, and if the Web client sends requests to both sites, the whole line should resemble the following:
    Const SE_VPS_VALUE = " domain=.contoso.com;"
  4. Save the file by using the .vbs file name extension. For example, use the following name to save the file:
    wplbCookieUserData.vbs
    Note Microsoft Visual Basic script files use the .vbs file name extension.
  5. At a command prompt, move to the location where you saved the .vbs file, type the following command, and then press ENTER:
    cscript wplbCookieUserData.vbs RuleName
    Note Replace the RuleName placeholder with the name of the Web publishing rule.
Note You can use this script to add any user data to the WPLB cookie. To do this, replace the value of the SE_VPS_VALUE constant with the user data that you want to add. Make sure that you end each field in the cookie with a semicolon.
STATUS
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 a similar problem, click the following article number to view the article in the Microsoft Knowledge Base:
937841 ISA Server 2006 forwards requests to an incorrect Web server when a client computer accesses Web sites that have different URLs in the same session
Properties

Article ID: 940242 - Last Review: 01/15/2015 17:20:06 - Revision: 1.0

  • Microsoft Internet Security and Acceleration Server 2006 Standard Edition
  • Microsoft Internet Security and Acceleration Server 2006 Enterprise Edition
  • kbnosurvey kbarchive kbtshoot kbexpertiseinter kbprb KB940242
Feedback