Intermittent connectivity problems

Use this information to solve intermittent connectivity problems.

Follow the suggested actions in the order in which they are listed in the Action column until the problem is solved.

  • Follow the suggested actions in the order in which they are listed in the Action column until the problem is solved.
  • See Parts listing, Types 7917, 7167, 2590 and 2584 to determine which components are customer replaceable units (CRU) and which components are field replaceable units (FRU) that must be replaced only by a trained service technician.
  • If an action step is preceded by "(Trained service technician only)," that step must be performed only by a trained service technician.
Symptom Action
Single compute node cannot connect intermittently
  1. Make sure that the network cables are correctly connected in the switch module ports and the switch module is correctly seated.
  2. Update the NIC device driver or the storage device controller device driver.
  3. See the documentation for the I/O module for resolving connectivity issues.
Two or more compute nodes cannot connect intermittently
  1. Using the diagnostic tools that are provided by the device manufacturer, test the I/O module that the devices are connected to.
  2. Attempt to connect one compute node to the network first, and connect other compute nodes, one by one, to try to isolate the problem.
  3. Update the I/O module firmware, if necessary.
    Note: Restarting the compute node and running POST diagnostics on the I/O module might also help isolate the problem; however, this might have other ramifications to the network.
Compute nodes are not discovered by the IBM® Flex System Manager management node or the CMM intermittently
  1. Make sure that the compute node is recognized by the IBM Flex System Manager management node or the CMM. It might appear as an unknown device in the chassis map. If it is not recognized, complete the following steps.
    1. Remove the compute node and inspect both the compute node and the back of the compute node bay to ensure that there is no physical damage to connectors.
    2. Move the compute node to another node bay.
    3. Replace the compute node.
  2. Make sure that the IBM Flex System Manager management node or the CMM can ping the compute nodes. If they cannot, see Cannot ping the IBM Flex System Manager management node on the management network.
  3. If the compute nodes are in another chassis, make sure that you have the proper software entitlements to manage that chassis with the IBM Flex System Manager management node.
  4. Check the IBM Support Portal for any firmware updates that might apply to this issue. You can view the release notes for a firmware update to determine the issues that are addressed by the update.
  5. Check the IBM Support Portal for any service bulletins that are related to network connectivity.
Parent topic: Troubleshooting by symptom