Troubleshooting RPC Endpoint Mapper errors using the Windows Server 2003 Support Tools from the product CD

The Dcdiag tool

The Dcdiag tool analyzes the state of domain controllers in a forest or in an enterprise and reports any problems to help in troubleshooting. You can use the Dcdiag tool to help troubleshoot RPC Endpoint Mapper errors when you run the Dcdiag tool. To do this, follow these steps:

1. Click Start, click Run, type cmd in the Open box, and then click OK.
2. Type dcdiag, and then press ENTER.

If RPC Endpoint Mapper problems exist, the Dcdiag tool may respond with error messages that are similar to the following:
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The Netdiag tool

You can use the Netdiag tool to help isolate networking and connectivity problems. You can use the Netdiag tool to help troubleshoot RPC Endpoint Mapper problems. To do this, follow these steps:

1. Click Start, click Run, type cmd in the Open box, and then click OK.
2. Type netdiag, and then press ENTER.

If RPC Endpoint Mapper problems exist, the Netdiag tool may respond with error messages that are similar to the following:




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The Repadmin tool

You can use the Repadmin tool for Active Directory replication, for troubleshooting Active Directory replication problems, and for troubleshooting RPC Endpoint Mapper problems. To do this, follow these steps:

1. Click Start, click Run, type cmd in the Open box, and then click OK.
2. Type Repadmin /bind, and then press ENTER.

If RPC Endpoint Mapper problems exist, the Repadmin tool may respond with an error message that is similar to the following:
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The Ntdsutil tool

Enterprise and domain administrators can use the Ntdsutil tool to manage and repair Active Directory, and to help troubleshoot RPC Endpoint Mapper problems. To help troubleshoot RPC Endpoint Mapper problems, follow these steps:

1. Click Start, click Run, type cmd in the Open box, and then click OK.
2. Type NTDSUtil ?, and then press ENTER.
3. At the ntdsutil: prompt, type Metadata cleanup, and then press ENTER.
4. At the metadata cleanup: prompt, type Connections, and then press ENTER.
5. At the Connections: prompt, type Connect to server localhost, and then press ENTER.

If RPC Endpoint Mapper Problems exist, the Ntdsutil tool may respond with an error message that is similar to the following:
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The Gpotool tool

You can use the Gpotool tool to check the consistency of Group Policy objects on domain controllers. The Gpotool tool is contained in the Windows Server 2003 Resource Kit. You can download the Windows Server 2003 Resource Kit by visiting the following Microsoft Web site:After you have installed the Resource kit, you can use the Gpotool tool to help troubleshoot RPC Endpoint Mapper problems. To do this, follow these steps:

1. Click Start, point to Programs, click Windows Resource Kit Tools, and then click Command Shell.
2. Type gpotool, and then press Enter.

If RPC Endpoint Mapper Problems exist, the Gpotool tool may respond with an error messages that are similar to the following:
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Event Viewer

The following events may be logged on a domain client, on a member server, or on a domain controller when RPC does not function correctly:
















On an enterprise certification authority server, or on a subordinate certification authority server, an event that is similar to the following may be logged:



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The Dcpromo tool

The Active Directory Installation Wizard (Dcpromo.exe) promotes Windows Server-based computers to be domain controllers. When the Dcpromo tool fails because of RPC problems, error messages that are similar to the following may appear in the DCPromo.log file.

Note The Dcpromo.log file is located in the %windir%\Debug folder.

Note These error codes represent the following:

• Error code 58 represents "The specified server cannot perform the requested operation."
• Error code 1722 represents "The RPC server is unavailable."
• Error code 1753 represents"There are no more endpoints available from the endpoint mapper."

Additionally, the DCPromoUI.log may report an error message that is similar to the following:
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The Active Directory Migration Tool

The Active Directory Migration Tool (ADMT) may generate events that are similar to the following in the Event Viewer on the computer where the ADMT is run:The log from Clonepr.vbs from %windir%\debug appears as follows:

clonepr t:0x5CC 00254        HRESULT = 0x800706D9 
 clonepr t:0x5CC 00255        Enter GetErrorMessage 800706D9 
 clonepr t:0x5CC 00256        Exit  GetErrorMessage 800706D9 
 clonepr t:0x5CC 00257        Enter SetComError Failed to add the source SID to the destination object's SID history. The error was: "There are no more endpoints available from the endpoint mapper. " 
 clonepr t:0x5CC 00258        Exit  SetComError Failed to add the source SID to the destination object's SID history. The error was: "There are no more endpoints available from the endpoint mapper. " 
 

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How to resolve RPC Endpoint Mapper errors

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

322756 How to back up and restore the registry in Windows

The "No more endpoints available" error message means the RPC Endpoint Mapper was not able to use a port greater than 1024 for a service that runs over RPC.
Note RPC Endpoint Mapper runs on port 135.

RPC can use ports up to 65535. By default, all versions of Windows use only ports 1024-5000. To repair the RPC Endpoint Mapper, follow these steps:

1. Verify the status and startup type for the following services on the server that gets the error:

   Type of computer	RPC service	RPC Locator service
   Windows Server 2003-based domain controller	Started, Automatic	Stopped, Manual
   Windows Server 2003-based member server	Started, Automatic	Stopped, Manual
   Windows Server 2003-based standalone server	Started, Automatic	Stopped, Manual
   Windows 2000 Server-based domain controller	Started, Automatic	Started, Automatic
   Windows 2000 Server-based member server	Started, Automatic	Started, Manual
   Windows 2000 Server-based standalone server	Started, Automatic	Stopped, Manual

   If you make any changes to the RPC service or to the RPC Locator service settings, restart the computer, and then test for the problem again.
2. Verify that the following keys exist in the registry (the keys are grouped according to operating system).
   
   Windows XP, Windows Server 2003 and Microsoft Windows 2000
   
   Verify that the ClientProtocols key exists under the HKEY_Local_Machine\Software\Microsoft\Rpcregistry subkey and that the ClientProtocolsentry contains at least the following five default values:
   

   Name	Type	Data
   ncacn_http	REG_SZ	rpcrt4.dll
   ncacn_ip_tcp	REG_SZ	rpcrt4.dll
   ncacn_nb_tcp	REG_SZ	rpcrt4.dll
   ncacn_np	REG_SZ	rpcrt4.dll
   ncacn_ip_udp	REG_SZ	rpcrt4.dll

   
   Note The ncacn_nb_tcp value does not occur in Windows XP.
   
   Microsoft Windows NT 4.0
   
   Verify that the ClientProtocolsentry exists under the HKEY_Local_Machine\Software\Microsoft\Rpcsubkey and that the ClientProtocolsentry contains at least the following six default values:
   

   Name	Type	Data
   ncacn_np	REG_SZ	rpcltcl.dll
   ncalrpc	REG_SZ	ncalrpc
   ncacn_ip_tcp	REG_SZ	RpcLtCcm.dll
   ncadg_ip_udp	REG_SZ	RpcLtCcm.dll
   ncadg_nb_tcp	REG_SZ	rpcltccm.dll
   ncacn_http	REG_SZ	rpcltccm.dll

   
   Microsoft Windows 98
   
   Verify that the ClientProtocolsentry exists under the HKEY_Local_Machine\Software\Microsoft\Rpcsubkey and that the ClientProtocolsentry contains at least the following four default values:
   

   Name	Type	Data
   ncacn_np	REG_SZ	rpcltcl.dll
   ncalrpc	REG_SZ	ncalrpc
   ncacn_ip_tcp	REG_SZ	rpcltc3.dll
   ncacn_http	REG_SZ	rpcltccm.dll

   
   For more information about related topics, click the following article number to view the article in the Microsoft Knowledge Base:
   
   
   325930 How to troubleshoot connectivity issues that are caused by RPC client protocol registry entries
   
   
   To verify the client registry settings, follow these steps:
   1. Click Start, click Run, type regedit, and then click OK.
   2. In Registry Editor, locate the following subkey:
      HKEY_Local_Machine\Software\Microsoft\Rpc
   3. Make sure that the five default values that were listed earlier are present. If some or all the values are missing, you can manually add the missing values when you right-click ClientProtocols, click New, and then click String value.
3. Verify that DNS is working correctly. To do this, follow these steps:
   1. On the computer that is experiencing error, click Start, click Run, type cmd, and then click OK.
   2. From the command line, type Netdiag -v or type ping -a IP_of_problem_server to make sure that the host record is resolving to the correct computer.
4. Verify that ports greater than 1024 are not blocked. Clients connect to RPC Endpoint Mapper on port 135. RPC Endpoint Mapper then tells the client which randomly assigned port between 1024-65535 a requested service is listening on. The ports may be blocked by a hardware firewall, a Internet Connection Firewall on Windows Server 2003-based computer and on a Windows XP-based computer, third-party firewall software, or antivirus software that has firewall functionality built-in. By default, port 135 TCP/UDP and ports 1024-65535 TCP must be open for RPC to work. However, you can restrict the ports greater than 1024 that RPC uses. However, RPC Endpoint Mapper is always on port 135.
   You can also use the Portqry tool to verify that the required ports are open. You must run the Portqry tool on a computer that is not receiving any RPC errors against a computer that is receiving RPC errors by using the -n switch. To this, follow these steps:
   1. Click Start, click Run, type cmd in the Open box, and then click OK.
   2. Type portqry -n problem_server -e 135.
      The output will appear similar to the following examples:
      
      

      Querying target system called:
      
        problem_server Attempting to resolve name to IP address...
      
       Name resolved to 169.254.1.1
      
       querying...
      
       problem_server TCP port 135 (epmap service): LISTENING
      
       Using ephemeral source port
       Querying Endpoint Mapper Database...
       Server's response:
       UUID: f5cc59b4-4264-101a-8c59-08002b2f8426 NtFrs Service
      ncacn_ip_tcp:65.53.63.16[1094]
      
       UUID: e3514235-4b06-11d1-ab04-00c04fc2dcd2 MS NT Directory DRS Interface
      ncacn_ip_tcp:65.53.63.16[1025]
      
       UUID: e3514235-4b06-11d1-ab04-00c04fc2dcd2 MS NT Directory DRS Interface
      ncacn_http:65.53.63.16[1029]
      
       UUID: e3514235-4b06-11d1-ab04-00c04fc2dcd2 MS NT Directory DRS Interface
      ncacn_http:65.53.63.16[6004]
       

   
   If port 135 is blocked, the following will appear:

   TCP port 135 (epmap service): NOT LISTENING 

   However, for these RPC Endpoint Mapper errors it is likely that ports greater than 1024 are blocked, and not port 135. From the output, you know the DC is using port 1094 for FRS and 1025, 1029, and 6004 for Active Directory replication. You can use the Portqry tool again to check those ports. For example, you can test all the ports at the same time by using the Portqry tool with the -o switch. For example, type
   
   portqry -n problem_server -o 1094,1025,1029,6004
   
   
   If the ports all respond as "LISTENING," its likely that blocked ports are not causing this problem. If any ports respond as "NOT LISTENING," the ports are probably blocked.
5. You can use the three REG_DWORD values that can be added to the HKEY_Local_Machine\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters subkey to help solve the RPC problem.
   Note None of the entries exist by default.
   
   
   • MaxUserPort
     This entry makes more ports available.
   • TcpTimedWaitDelay
     Reducing this value from its default setting of 240 seconds will make ports expire sooner. This parameter determines the length of time that a connection stays in the TIME_WAIT state when it is being closed. While a connection is in the TIME_WAIT state, the socket pair cannot be reused. This is also known as the 2MSL state because the value should be double the maximum segment lifetime on the network. See RFC 793 for more details.
   • TcpMaxDataRetransmissions
     The default value is 5. You may try 4 or 3, but do not try a value that is less than 3. This parameter controls the number of times that TCP retransmits an individual data segment (not connection request segments) before aborting the connection. The retransmission time-out is doubled with each successive retransmission on a connection. It is reset when responses resume. The Retransmission Timeout (RTO) value is dynamically adjusted by using the historical measured round-trip time (Smoothed Round Trip Time, or SRTT) on each connection. The starting RTO on a new connection is controlled by the TcpInitialRtt registry value.
6. If the HKEY_LOCAL_MACHINE\Software\Microsoft\Rpc\Internet registry key exists and has no values listed, then RPC only has one port available. By default, this registry key does not exist and if there are no values listed under this key, delete this key and then restart the server.

Note Other software programs may also cause RPC Endpoint Mapper errors, such as the following:

• Noblenet Portmapper.
  This utility requires a host file pointing to itself to work correctly. Editing the host file may resolve the issue.
  
• BMC Patrol agent software using the AD Knowledge Module (KM).
  In this case, update to the latest version, at least 1.4.01.
  
• Incompatible network adapter drivers.
  In this case, upgrade to the latest Windows Hardware Quality Labs (WHQL) signed driver version.

Note If you do not want to continue troubleshooting, you might want to ask someone for help.Or, you might want to Contact Support.

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