Forum Discussion

0x0ff_info_1420's avatar
0x0ff_info_1420
Icon for Cirrus rankCirrus
Mar 11, 2015

My VS is unknown (Blue) on my LTM but available on my GTM (Green)

Hi,

 

I'm working on GTM currently. I'm wondering why when I add a LTM on my GTM and discover the existing VS, my GTM find them and considers they are available (Green) when at the same time, on my LTM the same VS are in an unknown state (Blue). There is no Health Check on my LTM or on my GTM.

 

Is there a way to reflect the blue status on the GTM, or it's a normal behavior ? Can you tell me what is the logic behind this choice, I just working on it since few weeks.

 

Regards

 

BIG-IP DNS
design

6 Replies

Sort By
  • 0x0ff_info_1420's avatar
    0x0ff_info_1420
    Icon for Cirrus rankCirrus
    Mar 11, 2015

    There is no HealthCheck on LTM and GTM neither. I add this clarification to my first post.

     

  • Max_Q_factor's avatar
    Max_Q_factor
    Icon for Cirrocumulus rankCirrocumulus
    Mar 11, 2015

    I am not certain but I believe that this behavior is consistent with the same philosophy that a node not having a monitor and being blue but a pool having a monitor and the pool member being green.

     

    In this case, the GTM may be using the bigip monitor (by default) for the LTM, and since the VS is blue the VS inherits the green from the bigip monitor that the GTM is using for the LTM.

     

  • 0x0ff_info_1420's avatar
    0x0ff_info_1420
    Icon for Cirrus rankCirrus
    Mar 11, 2015

    Thanks to you for reply,

     

    A monitor can be specified on GTM, and used to check availability. In this case, even without HealthCheck on the LTM Pool (blue pool), it's normal for the GTM to see the VS available (because someone proceed the test). But in my case, there is no monitor at all (LTM or GTM).

     

    • Max_Q_factor's avatar
      Max_Q_factor
      Icon for Cirrocumulus rankCirrocumulus
      Mar 11, 2015
      When you add a LTM server to GTM, even if you do not add a monitor to the LTM the GTM adds the bigip monitor to the server by default
    • 0x0ff_info_1420's avatar
      0x0ff_info_1420
      Icon for Cirrus rankCirrus
      Mar 11, 2015
      I'm not sure the bigip monitor check VS availabilities. In my case, if availability is checked, the VS should be Red because the Real Servers of the LTM pools are dummies servers (so they don't answer). Beside my first question, do you know what exactly, the bigip monitor do ?