Cannot connect to machine
Posted: October 29th, 2008 | Author: TnT Admin | Filed under: Errors | Tags: Controller, Errors | 1 Comment »“Cannot connect to machine <machine name>”
When adding Windows Resource measurement on the LoadRunner Controller, the add was unsuccessful and returns a “Cannot connect to machine…” error with a bunch of suggestions to keep you busy… Before you move on in this article, do take a look at two articles, namely, “How-to configure Windows System Resource monitoring” and Document ID: KM304905: Error: “Monitor name: Windows Resources. Cannot connect to machine…” on the configurations required. Apply them first before moving on.
If error persists after configuring the Windows Resource from the two documents, the next step that you do is to validate the necessary setup from perfmon. What must be working are, (a) perfmon is running on the target machine and (b) TCP 139 must be opened for the communication on a two-way communication. Some steps here are repetition of the configuration as mentioned above, however, it’s advisable to re-validate the setup:
[1] Validate network setup
- Launch command prompt
- Ping from the command prompt, Run > cmd the SUT from the Controller. Command as followed: ping <target_machine>. If the Ping test fail, it’s straight-forward on the following few possibilities: (a) target machine is not up, (b) firewalls or target machine is preventing network pings.
- Telnet from the command prompt, Run > cmd the SUT from the Controller on port 139. Command as followed: telnet <target_machine> 139. The expected result that if the connectivity is ok on TCP 139, the command prompt will turn full black. If it fails, it will return “Connecting To <target_machine>…Could not open connection to the host, on port 13
9: Connect failed” which can be a likely caused of firewall misconfiguration at the (a) network level (e.g. disallow/block ports or IP filtering on firewall) or at the target machine level (e.g. ZoneAlarm or Windows Security).
[2] Validate target machine setup (NTFS)
- At the target machine, launch perfmon.
- Ensure perfmon is running. If perfmon is not running, it can be caused by corruption of perfmon which may require re-installation of perfmon (Windows OS).
- Now, launch perfmon from the Controller, and connect from Controller’s perfmon to target_machine in “Select counters from computer:”. If it connects, then you will be able to retrieve the counters. If not, which response with “Unable to connect to machine”, you will need to ensure the following to be configured.
- In the target_machine, launch the Services.msc from Run. Ensure the following services are started: Network DDE DSDM, Network DDE and Remote Registry. Usually they are turned off due to hardening policy.
- Launch regedit from Run. Naviigate to the following registry keys and ensure that READ access is granted to them:
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Perflib
- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurePipeServers\winreg
- Disable Simple File Sharing. Launch Folder Explorer in target_machine > > Tools > Folder Options > View > at the bottom of “View all settings”, disable “Use simple file sharing (Recommended)”.
- Launch Folder Explorer and type %SYSTEMROOT% in the address bar. Navigate to %SYSTEMROOT%\System32. Allow READ access for all users on two files, namely, Perfc009.dat and Perfh009.dat. (NOTE: Ensure the user being granted the READ rights is the one being used for monitoring from Controller. If not, do create an additional account for it.)
- Now, go back to Controller’s perfmon and connect to the target_machine again in “Select counters from computer”. You should be able to see the counters from the target machine.
- Now, go back to Controller and connect to the target_machine which should have resolve the problem.
Nice article…it helps…!!