F5 | 1128369

On affected versions of BIG-IP DNS, targets monitored with a "bigip" type monitor may show as 'big3d: timed out', or flap between that state and green. ... While there can be many causes of the 'big3d: timed out' state (which indicates that a GTM monitor probe reply was expected, but not received within the timeout period), this particular cause is due to the order that the probes are sent, resulting in a bunching effect, where all the probes related to the same big3d (LTM) device are sent in rapid succession, leading to the message buffer between big3d and mcpd on the LTM becoming congested. ... When gtmd schedules monitor probes, all the probes with the same interval are grouped together and spread out across the interval period. ... The issue is that within that list, monitors for the same gtm server can be grouped together, causing them to be sent to big3d in rapid succession. ... When this happens, some of the messages relating to BIG-IP monitor probes may be dropped, and no re...