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Allwin_179373's avatar
Allwin_179373
Icon for Nimbostratus rankNimbostratus
Jun 27, 2018

GTM Pool communication

We have 4 DCs created one for each GTM DC (DC1, DC2, DC3 and DC4). All the 4 GTMs are part of the same GSLB Sync group.

 

I created one DC3 generic host server and associated that server to data center DC3 to which it belongs, but the server won't come up, when the health monitor is assigned to it.

 

But, when I associate that server with data center DC1, the server comes up, using the same health monitor.

 

At first I though that connectivity might be an issue, but we are able to telnet to the server from the DC3 GTM.

 

Anything I might be missing here, I checked the routing and firewall rules, all seems fine, but still when associated with its own DC its not coming up.

 

Any ideas??

 

application delivery
BIG-IP DNS
  • Leonardo_Souza's avatar
    Leonardo_Souza
    Icon for Cirrocumulus rankCirrocumulus
    Jun 27, 2018

    When you have multiple GTMs, only one of them will be responsible for choosing who will monitor. That could be one of the GTMs, or any other BIG-IP device. GTM will first try to pick a BIG-IP in the same data center.

    In your case is possible that is picking, for example, an LTM in that data center, if you have one. Also, telnet does not do the same test as the monitor, in case you are using something more complex than a TCP monitor.

    Enable this db key, and see if you can get more information:

    tmsh modify sys db gtm.debugprobelogging value enable

    This will log to /var/log/gtm. If in production, don't leave that enable and enable just during the tests.

    You can also use prober pools, to tell who you want to monitor.