Troubleshooting ‘RPC server unavailable’ 0x800706BA

Issue: You are getting the error: “The RPC Server is unavailable. (Exception from HRESULT: 0x800706BA)”

Cause: This error is likely caused by the RPC ports being blocked between the servers involved in the communication or server process you are trying to complete.

Background: RPC is categorized as the X11 protocol and is in the 6001 to 6032 port range.  Commonly 6007 is what is being blocked in this case.

Diagnosis: You can test RPC connectivity from the server you are on to another computer/server using the following command:
Get-WmiObject Win32_ComputerSystem –ComputerName OTHERSERVER
If communications fail you will see output similar to the following:
rpc-server-unavailable-0x800706BAIf RPC communications are working between the servers you will output similar to the following:

You can also test specific ports, like 6007 using the telnet command.  If telnet is successful and the port is open then you will see a blank screen.  If telnet fails because the port is closed then it will simply time out as you can see in this example:
Resolution: Work on your firewall policies to make sure RPC is not being blocked.  Many firewalls (Watchguard) will block RPC and SMB/NetBios (NetScreen) even when you have ‘any-any’ rules in place.  In the case of WatchGuard you must specifically create a rule/policy to explicitly allow the RPC ports.  In the case of NetScreen (ScreenOS) there is a checkbox in the rule to allow NetBios.


4 thoughts on “Troubleshooting ‘RPC server unavailable’ 0x800706BA

  1. Supriya


    I’m receiving ERROR : The RPC server is unavailable. (Exception from HRESULT: 0x800706BA).
    Firewall and antivirus are off.
    Still receiving the error.
    In the working server(In which im not receiving RPC error) tried telneting from 6001 – 6032 to check in which port its listening.Its not listening in any of these ports.
    Kindly let me how to fix the error and also to check in which port does RPC listening to.

    Thank you.

    1. Chris Post author

      Hi Supriya, If telnetting on the RPC ports is not connecting that may mean the ports are being blocked. If you want to determine if the destination server is listening you could telnet to itself on the ports. That said, I’d recommend using the test methods in the article that are contained in the diagnoses section rather that telnet. The ports RPC uses are outlined in the article as well. Is there a firewall between your source and destination and are they on the same subnet?

  2. HaeRim Lee

    Hello Chris
    There are two processes A.exe and B.exe on the same PC.
    B.exe is out-of-server COM process and A.exe is using one of B’s interfaces.
    When A.exe calls one of A’s methods, I experience 0x800706BA from time to time.
    Is there any way to find what is blocking this call?

    Thank you.


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