Bug ID 420498: DNS transparent cache does not differentiate queries regardless of RD bit

Last Modified: Apr 10, 2019

Bug Tracker

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

Known Affected Versions:
11.2.0, 11.2.1, 11.3.0, 11.4.0, 11.4.1

Fixed In:
11.5.0, 11.4.0 HF3, 11.3.0 HF6, 11.2.1 HF8

Opened: May 03, 2013
Severity: 3-Major
Related AskF5 Article:
K14855

Symptoms

If a query that does not have the RD bit set is answered by a virtual server with transparent cache enabled, a subsequent query for the same query name with RD bit set will get an answer that was cached for the non RD query.

Impact

If the responses for a query with and without RD bit set are different, the response for query with RD bit set may have an empty answer section.

Conditions

DNS profile enables Transparent cache. The subsequent is answered by cache.

Workaround

Disable transparent cache.

Fix Information

If a query that does not have the RD bit set is answered by a virtual server with transparent cache enabled, a subsequent query for the same query name with RD bit set will get a correct answer.

Behavior Change