Bug ID 757775: Added DB variable to force setting RA bit in response from cache

Last Modified: Feb 20, 2020

Bug Tracker

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

Known Affected Versions:
13.1.0,,,,,,,,, 13.1.1,,,,,, 13.1.3,,, 14.0.0,,,,,, 14.0.1,, 14.1.0,,,,,,, 14.1.2,,,, 15.0.0, 15.0.1,,

Fixed In:

Opened: Feb 06, 2019
Severity: 3-Major


Under certain conditions, a response from Transparent cache may not have the RA (Recursion Available) bit set.


A response from Transparent cache does not have RA bit set.


The issue takes place under the following conditions: -- Response going from a transparent cache. -- The msg sub-cache does not contain the query. -- The rrset sub-cache does contain the query.


The following iRule resolves the issue: When DNS_RESPONSE { DNS::header ra 1 }

Fix Information

Added new DB variable dnscache.forcerecursionavailablebit which, when enabled, forces setting the RA bit in responses coming from any type of cache.

Behavior Change