Check Point blocks certain AD Trafic

Remote Procedure Call-based operations may fail if certain firewall and VPN products deny network requests. This denial occurs if the network requests come from Microsoft Windows Server 2003 Service Pack 1-based computers. These network requests may fail on computers where you apply Windows Server 2003 Service Pack 1 (SP1) to a Windows Server 2003-based computer or your OEM or retail installation media includes SP1 updates. The following products may deny these network requests:

•	Firewall or virtual private network (VPN) products from Checkpoint Software Technologies
•	Microsoft Internet Security and Acceleration (ISA) Server

Note As of May 2005, the previous list includes the products that Microsoft has determined may deny these network requests. However, the previous list may not include every possible product that performs application-level filtering and that can deny network requests. Hardware and software from other manufacturers that perform application-level filtering may also deny remote procedure call (RPC) requests from computers that are running Windows Server 2003 Service Pack 1 (SP1).

This issue occurs because Windows Server 2003 SP1 adds support for some new transfer syntaxes to the RPC implementation. These new transfer syntaxes are known as "multiple transfer syntax negotiation." They help 32-bit and 64-bit computers handle larger workloads. Additionally, they frequently help 32-bit and 64-bit computers work faster.

Specifically, firewalls and VPN products that do permit more than one presentation context to be present in a bound RPC protocol data unit (PDU) may cause either of the following symptoms:

•	Drop RPC frames on the network
•	Prematurely close connections from Windows Server 2003 SP1-based computers

To resolve this issue, if RPC-based operations on Windows Server 2003-based computers fail across a VPN or a firewall immediately after you install Windows Server 2003 SP1, contact your firewall or VPN vendor to see if an updated version of their RPC filter is available. If RPC-based operations are being blocked by filters on Microsoft Internet Security and Acceleration Server (ISA) 2000, or ISA Server 2004 Standard Edition computers, see Microsoft Knowledge base article: 887222: The ISA Server RPC filter blocks RPC traffic after Windows Server 2003. If RPC-based operations are blocked by filters on Check Point Software products, see Check Point Software SecureKnowledge article SK30784, or visit the following Checkpoint Software Web site:

To work around this issue, use either of the following methods.

Method 1

You can disable RPC filters on firewalls and VPN products if the network requirements make this possible.

Method 2

If you need RPC-based operations to function immediately and you cannot update firewalls and VPNs in a timely manner, install the hotfix that is described in this section and then follow these steps:

1.	Click Start, click Run, type regedit, and then click OK
2.	Locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Rpc
3.	Click the Edit menu, point to New, and then click DWORD Value.
4.	Type Server2003NegotiateDisable as the name of the new DWORD Value
5.	Right-click Server2003NegotiateDisable, and then click Modify.
6.	In the Value Data box, type 1, and then click OK. Note This setting disables the bind time negotation and multiple transfer syntax negotiation.
7.	Quit Registry Editor. Restart the Windows Server 2003-based computer.
8.	After the firewalls and VPN devices are compatible with RPC on the computer that has Service Pack 1 installed, set the value for the Server2003NegotiateDisable entry in the registry to 0. Then, restart the Windows Server 2003-based computer.

Hotfix information

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it 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 Windows Server 2003 that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product 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. 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 tool in Control Panel.

File information

   Date        Version        Size       File name   Platform
   ----------------------------------------------------------
   05-03-2005  5.2.3790.2436   642,048   Rpcrt4.dll  x86
   05-03-2005  5.2.3790.2436  1,714,688  Rpcrt4.dll  x64
   05-03-2005  5.2.3790.2436  2,462,208  Rpcrt4.dll  IA-64

Administrators are advised to evaluate whether RPC filter definitions in network infrastructure devices are compatible with the Windows Server 2003 SP1 RPC traffic. An administrator should do this evaluation before deployment of either firewall/VPN devices or Windows Server 2003 SP1 in production environments where such network devices are deployed.

Evaluation is especially appropriate where firewalls can filter RPC-based replication traffic between domain controllers. Filtration of RPC-based replication traffic between domain controllers can cause a long-term interruption of Active Directory replication.

Specifically, administrators should try to use monitoring software to make sure that all domain controllers in a forest perform incoming replication within a rolling tombstone lifetime number of days. By default, a rolling tombstone lifetime number of days is 60 days. Domain controllers that cannot perform incoming replication of knowledge of each unique delete within the previous tombstone lifetime number of days will forever be inconsistent for those changes until an administrator intervenes.

Events in the Directory Service event log that indicate that Active Directory replication is failing on Windows Server 2003-based domain controllers include the following:

•	1862: “the local DC has not recently received replication information from a number of domain controllers” (intersite)
•	1864: “the local DC has not recently received replication information from a number of domain controllers” (intrasite)
•	2042: “it has been too long since this machine last replicated with the named source” (TSL # of days)

If administrators do not have a monitoring solution, they can use enterprise administrator credentials to run the following Windows Server 2003 REPADMIN command daily: Administrators can view the Showrepl.csv file in a program like Microsoft Excel that parses comma-separated text. A high priority task includes resolving replication failures on destination domain controllers that have failed incoming replication for the longest time.

Repadmin.exe is located in the Support\Tools\ Suptools.msi file on the Windows Server 2003 installation media.

For more information about how to remove lingering objects, click the following article number to view the article in the Microsoft Knowledge Base: For more information about programs from Checkpoint Software Technologies, visit the following Checkpoint Software Technologies Web site: For more information about ISA Server, visit the following Microsoft Web site: Microsoft is not aware of any router or switches that perform program–level filtering that would interfere with RPC-based operations in Windows Server 2003 SP1.

The following error message is typically displayed by components when RPC frames with multiple transfer syntaxes are rejected by a firewall or a VPN generates Windows 32 error 1727: This generic error code has multiple root causes and does not uniquely identify the blocking of RPC frames from Windows Server 2003 SP1-based computers.

For information about the DCE RPC specification, visit the following Opengroup Web site: For information about multiple transfer syntax support in the DCE RPC specification, visit the following Opengroup Web site: The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.