Product Documentation

Troubleshooting High Availability Issues

Jul 29, 2013

The most common high availability issues involve the high availability feature not working at all, or working only intermittently. Following are common high availability issues, and probable causes and resolutions.

  • Issue
    The inability of the NetScaler appliances to pair the NetScaler appliances in a high availability setup.
    • Cause

      Network connectivity

      Resolution

      Verify that both the appliances are connected to the switch and the interfaces are enabled.

    • Cause

      Mismatch in the Password for the default Administrator account

      Resolution

      Verify that the password on both the appliances is the same.

    • Cause

      IP conflict

      Resolution

      Verify that both the appliances have unique NetScaler IP (NSIP) address. The appliances should not have the same NSIP address.

    • Cause

      Node ID mismatch

      Resolution

      Verify that the Node ID Configuration on both the appliances is unique. The appliances should not have the same Node ID configuration. Additionally, you must assign value for a Node ID between 1 and 64.

    • Cause

      Mismatch in the password of the RPC node

      Resolution

      Verify that both the nodes have the same RPC node password.

    • Cause

      An administrator has disabled the remote node

      Resolution

      Enable the remote node.

    • Cause

      The Firewall application has blocked the heartbeat packets

      Resolution

      Verify that the UDP port 3003 is allowed.

  • Issue
    Both the appliances claim to be the primary appliance.
    • Cause

      Missing heartbeat packets between the appliances

      Resolution

      Verify that the UDP port 3003 is not blocked for communication between the appliances.

  • Issue
    The NetScaler appliance is not able to synchronize the configuration.
    • Cause

      A Firewall application is blocking the required port.

      Resolution

      Verify that the UDP port 3010 (or UDP port 3008 with secure synchronization) is not blocked for communication between the appliances.

    • Cause

      An administrator has disabled synchronization.

      Resolution

      Enable synchronization on the appliance that has the issue.

    • Cause

      Different NetScaler releases or builds are installed on appliances.

      Resolution

      Upgrade the appliances to the same NetScaler release or build.

  • Issue
    Command propagation fails between the appliances.
    • Cause

      A Firewall application is blocking the port.

      Resolution

      Verify that the UDP port 3011 (or UDP port 3009 with secure propagation) is not blocked for communication between the appliances.

    • Cause

      An administrator has disabled command propagation.

      Resolution

      Enable command propagation on the appliance that has the issue.

    • Cause

      Different NetScaler releases or builds are installed on appliances.

      Resolution

      Upgrade the appliances to the same NetScaler release or build.

  • Issue
    The NetScaler appliances in the high availability pair are unable to run the force failover process.
    • Cause

      The Secondary node is disabled.

      Resolution

      Enable the secondary node.

    • Cause

      The Secondary node is configured to stay secondary.

      Resolution

      Set the secondary high availability status of the secondary node to Enable from Stay Secondary.

  • Issue
    The secondary appliance does not receive any traffic after the failover process.
    • Cause

      The upstream router does not understand GARP messages of NetScaler appliance.

      Resolution

      Configure Virtual MAC (VMAC) address on the secondary appliance.