Unstable system/network adapter diagnosis illustrates how a system or network adapter is diagnosed as being unstable.

  1. Up

  2. Down

  3. 80 secs

  4. idle

  5. 1st Trap

  6. Last Trap

  7. idle

  8. waiting

  9. Send

  10. Unstable

  11. Notification

  12. Clear

  13. Unstable

  14. Notification

  15. 80 secs

  16. unstable

Figure 1. Unstable system/network adapter diagnosis

In the example, assume that the Link/RestartTrapWindow parameter has a value of 30 seconds and that the Link/RestartTrapThreshold parameter has a value of 2.

IP Availability Manager performs the following actions:

  1. As soon as IP Availability Manager receives a linkDown trap from a physical port or interface (or a coldStart/warmStart trap from a system), it begins counting.

  2. When IP Availability Manager receives two or more traps within the 30-second Trap Window, it considers the network adapter or system to be unstable and sends an Unstable notification. The Minimum Traps variable (set by the Link/RestartTrapWindow parameter) determines the number of traps (2) that IP Availability Manager must receive within the Trap Window (set by the Link/RestartTrapWindow parameter) before IP Availability Manager considers an object unstable.

  3. IP Availability Manager continues to receive traps for 80 seconds after the initial trap. This results in a Stable Time of 80 seconds.

    The Stable Time is the amount of time IP Availability Manager waits before it clears the Unstable notification. In our example, the Stable Time is set at 80 seconds since it is greater than the Trap Window (30 seconds) and less than one hour.

    As you can see, IP Availability Manager uses a relative measure to determine how long an object must be stable before it clears the Unstable notification. This measure is proportional to the amount of time an object is unstable. The longer an object is unstable the longer it must be stable before the Unstable notification is cleared. Because the object in our example remains unstable for 80 seconds, IP Availability Manager clears the Unstable notification no sooner than 80 seconds after it receives the final trap.