Last Modified: Dec 21, 2024
Affected Product(s):
BIG-IP APM
Known Affected Versions:
14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 14.1.3.1, 14.1.4, 14.1.4.1, 14.1.4.2, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4, 15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1
Fixed In:
16.0.0, 15.1.4, 14.1.4.3
Opened: Feb 05, 2020 Severity: 1-Blocking
DNS queries are not being cached on the BIG-IP device.
DNS queries are forwarded, but the BIG-IP system does not cache them.
-- DNS cache is enabled (System :: Configuration : Device : DNS Cache). -- Device receives DNS queries.
None.
DNS queries are now cached when DNS Cache is enabled.
Full DNS cache functionality has been restored. This results in performance degradation. You might notice it in OCSP performance, when compared to releases in which full DNS cache functionality is not present. By default, DNS cache is disabled. To recapture performance, enable DNS cache. Given design change of APM related DNS request handling, now name server order may not be strictly honored. That means, when there are multiple name-servers configured under "System >> Configuration : Device : DNS : DNS Lookup Server List" ("sys dns name-servers" in CLI), BIG-IP sends DNS request to 'faster' name server based on internal srtt value. This is done by APM specific daemon "dnscached".