Bug ID 647868: bigd monitor stuck in fqdn-checking when DNS server unreliable

Last Modified: Nov 22, 2021

Bug Tracker

Affected Product:  See more info
BIG-IP TMOS(all modules)

Known Affected Versions:
14.0.0, 13.0.0, 12.1.3, 12.1.2, 12.1.1, 12.1.0, 12.0.0, 11.6.1

Opened: Feb 27, 2017
Severity: 2-Critical


FQDN monitors may be stuck in status 'fqdn-checking' in environments with an unreliable DNS server, such as when DNS queries frequently timeout.


FQDN monitor status remains in 'fqdn-checking', even after the DNS server again becomes available. Monitors may eventually become "un-stuck", and monitors will (correctly) reset upon system restart.


FQDN monitors are configured; and the DNS server used to resolve FQDN nodes is intermittently available, leading to occasional timeouts to bigd from DNS queries.


Although there is no workaround, FQDN monitors are not recommended for use in environments where DNS servers are unreliable.

Fix Information


Behavior Change