Bug ID 475074: Very large GTM monitoring configs can fail monitors.

Last Modified: Jul 18, 2026

Affected Product(s):
BIG-IP GTM(all modules)

Known Affected Versions:
11.5.1, 11.5.1 hf1, 11.5.1 hf2, 11.5.1 hf3, 11.5.1 hf4, 11.5.1 hf5, 11.5.1 hf6, 11.5.1 hf7, 11.5.1 hf8, 11.5.1 hf9, 11.5.1 hf10, 11.5.1 hf11, 11.5.2, 11.5.2 hf1, 11.5.3, 11.5.3 hf1, 11.5.3 hf2, 11.5.4, 11.5.4 hf1, 11.5.4 hf2, 11.5.4 hf3, 11.5.4 hf4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.0 hf1, 11.6.0 hf2, 11.6.0 hf3, 11.6.0 hf4, 11.6.0 hf5, 11.6.0 hf6, 11.6.0 hf7, 11.6.0 hf8, 11.6.1, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3

Opened: Aug 08, 2014

Severity: 3-Major

Symptoms

When monitoring a very large number of virtuals, GTM can mark objects down. The log shows: alert gtmd[xxxx]: xxxxxxxx:x: Monitor instance /Common/bigip xx.xx.xx.xx:80 UP --> DOWN from /Common/xxxx (no reply from big3d: timed out)

Impact

Load balancing can be disrupted because the status of the virtual server is being marked unavailable.

Conditions

GTM monitors a very large number of virtuals with maximum synchronous monitor requests set very high.

Workaround

Set your gtm.global-settings.metrics.max-synchronous-monitor-requests to a value which does not overwhelm the big3d on the other box.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips