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kev_245_28249's avatar
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Feb 20, 2012

Gtm - Verify Server Availability

if the gtm has the following:


an object that it monitors with say a 31 second timeout. 5 second probe interval


and the default verify server availability is ticked


the host is unresponsive but the 31 seconds has not timed out



1/ Will the Gtm prior to handing out a dns request, only refer to its monitor status, or will it verify the end host by sending traffic to it? ie, does verify server availability overide the health monitor timeout setting?



how will the answer change if:


2/ service on action down = reject


3/ if the Ltm is doing the monitoring (not the Gtm) and reporting over iquery, with the same condition, the monitor has not expired, but the host is actually down.

4 Replies

  • Hi kev_245,


    The GTM will respond based on current state at time of request. If it's own monitors or the bigip monitor state is up when the request is received, it will answer appropriately. As soon as it knows there is an outage, it will fallback to whatever mechanism you have in place. At the local level, you can do some things to handle that (redirects / rewrites to alternative pools /etc) but at GTM level, you rely on your monitoring.
  • Hi, thanks for your reply.


    By "as soon as it knows of an outage" do you mean if one probe times out or only if the monitor has timed out?



    From what I've found out since the post, it sounds like verify server availability is more so for the period when you add a new monitor.