Maintaining existing stack nodes

You can put a Stack Node in standby mode to allow for upgrades and maintenance while the remaining stack is active. With this capability, you can upgrade each of your Stack Nodes, while the in-service appliances continue to capture data. Before you can upgrade the Stack Controller, you must disable data capture and take the entire stack offline.

Before you begin

Ensure that you update all Stack Nodes before you update the Stack Controller.

About this task

When an appliance is in standby mode, you can upgrade the operating system and application software of the appliance. If the appliance does not need to be restarted, connectivity between the appliance and the stack ring is maintained. If the appliance is actively capturing data when standby mode is enabled, the stack switches immediately to another appliance for active capture.

If an update affects communications with the Stack Controller, for example an update to protocols, the Stack Nodes can handle this during the update process because they are backward compatible with protocols and commands that are sent from the Stack Controller.

A Stack Node in standby mode has the following characteristics:
  • Continues to appear in the stack list in the STACKING widget.
  • Maintains stack ring connectivity.
  • Maintains group membership.
  • Includes capture data in searches.
  • Is not used as an active capture device in the stack; new data is not captured to this appliance.

You cannot put the Stack Controller into standby mode without a service interruption because it is the only appliance that has the TAP port, and it distributes the data to all appliances in the stack.

Procedure

  1. In the STACKING widget, select the appliance that you want to work with, and then click Standby.
    Note: To allow the maximum time to apply updates to the appliance, select the stack node that has the newest First packet and Last packet timestamp, but that is not currently capturing data.
  2. Apply the updates to the standby appliance.
  3. When the maintenance is complete, in the STACKING widget, select the appliance and then click In Service to re-enable it.