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:
get-wmiobject-rpc-test

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:
telnet-6007-rpc-test
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.

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One thought on “Troubleshooting ‘RPC server unavailable’ 0x800706BA

  1. 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.

    Reply

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