Bug ID 723288: DNS cache replication between TMMs does not always work for net dns-resolver

Last Modified: Nov 07, 2022

Bug Tracker

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

Known Affected Versions:
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, 12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5

Fixed In:
14.1.0.6, 14.0.0.5, 13.1.1.4, 12.1.4.1, 11.6.5.3

Opened: Jun 06, 2018
Severity: 3-Major

Symptoms

System DNS resolvers (net dns-resolver objects) do not share DNS reply information between the dns resolver instances across TMMs, which can result in separate TMMs performing seemingly-unnecessary DNS lookups.

Impact

A performance impact resulting from each TMM having to perform unnecessary DNS lookups.

Conditions

There are no LTM DNS *cache* objects present in the BIG-IP configuration.

Workaround

Use tmsh to create a placeholder LTM DNS cache resolver object. The object does not need to be used anywhere, just present in the config. Note: This workaround is effective even without a DNS license (although in that case, the placeholder object must be created using tmsh, as the GUI menu would not be available without a DNS license.)

Fix Information

None

Behavior Change