RPC Server is Unavailable (0x800706ba) (4229019)

A "0x800706ba : RPC Server is Unavailable" error is encountered when trying to add a new Operating System (OS) connection or validating an existing OS connection.

Could not connect to 192.168.0.1 or MYSERVER. RPC Server Unavailable (0x800706ba). The computer did not respond at all. This could be because there is a firewall blocking communication, or because WMI is not enabled on the computer. See the link below for more information on correcting the error.

CAUSE #1

This error is normally caused by firewall. RPC Server Unavailable generally means that the FglAM was able to connect on ports 135/445 but the ephemeral port connection back to the FglAM server was not successful. Windows RPC connections initially connect on 135/445 and the server being called randomly selects a port above 1024 to connect back to the FglAM server, it is this connection back that is not successful.

CAUSE #2
RPC service or remote registry service on the monitored host is not running

CAUSE #3

This issue can also occur if a NAT is in place. Windows RPC/DCOM connections are have problems NAT'ed connections.

CAUSE #4
Time sync between the Agent Manager and the Monitored Host

CAUSE #5

The issue can occur if there is an IPSec setting that only allows connections to the monitored from designated hosts.

SOLUTION #1  * This is the most common cause * 

DCOM connections for WMI use a range of dynamic ports detailed here. For easier configuration we recommend using a single fixed static port for DCOM/WMI port monitoring as described in KB 4289831.

Since the agent connects remotely (that is, from an external source) the Windows Firewall can interfere with operations. In such cases, it is recommended that you initially try disabling the firewall to determine if that allows the agent to connect. When the agent can connect with the firewall disabled, re-enable it and open the following ports:

• TCP Port 135 (DCE/RPC Locator service, WindowsShellService, WMIConnectionService)
• TCP Port 139 (NetBIOS Session Service)
• TCP Port 445 (Windows shares)
• TCP Port range 49152 to 65535 (Dynamic RPC ports)

On the monitored host, enable the Inbound rule for Remote Administration (RPC), Windows Management Instrumentation (WMI), or Remote Service Management (RPC)

Windows XP/Server 2003:

1. Click Start
2. Click Run
3. Type cmd and press key
4. In the command prompt type netsh firewall set service remoteadmin enable
5. Press key

Windows 7 / Server 2008:

1. Click Start
2. Click Run
3. Type cmd and press key
4. In command prompt window type  netsh advfirewall firewall set rule group="Windows Management Instrumentation (WMI)" new enable=yes
5. Press key
6. In the command prompt type  netsh advfirewall firewall set rule group="remote administration" new enable=yes
7. Press key

SOLUTION #2 
On the monitored host, start the RPC service and remote registry service in the Windows services console.

Please see Microsoft article "How to configure RPC dynamic port allocation to work with firewalls" at https://support.microsoft.com/en-us/kb/154596

SOLUTION #3
Move the FglAM server to the same side of the NAT device as the server being discovered to avoid the NAT altogether.

SOLUTION #4
Verify that the Time on the Monitored Host is the same as the Agent Manager.

SOLUTION #5

Revise the IPSec setting so that connections can be made from the FglAM host to the monitored host.

Microsoft Technet "Troubleshooting The RPC Server is available"
http://social.technet.microsoft.com/wiki/contents/articles/4494.troubleshooting-the-rpc-server-is-unavailable.aspx

Here is some information on the ports for the WMI from our Agent Manager installation guide that should provide further information on the ports required for WMI.