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

Last Modified: Jul 12, 2023

Affected Product(s):
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

Symptoms

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

Impact

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.

Conditions

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.

Workaround

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

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips