Bug ID 1302825: Allow configuration of the number of times the CNAME chase is performed

Last Modified: May 29, 2024

Affected Product(s):
BIG-IP DNS, LTM(all modules)

Known Affected Versions:
15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8,,, 15.1.9,, 15.1.10,,,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,,,,, 16.1.4,,,, 17.1.0,,,

Fixed In:

Opened: May 29, 2023

Severity: 3-Major


The client receives a SERVFAIL when the CNAME queried to the BIG-IP DNS resolver takes more than the limit configured in the DNS Cache. The limit is set as 11 for BIG-IP v17.1.0 and later. It is fixed as 8 for earlier releases.


The clients cannot resolve DNS names if the count of the CNAME chases goes beyond the limit configured in the DNS cache.


A BIG-IP DNS is configured as a resolver (as a cache or a net resolver). The domain of which CNAME resolution is asked requires chasing more times than what is pre-configured in the DNS Cache.


The providers whose CNAME is queried can be asked to keep chains shorter than the pre-configured limits (the limits vary between different versions of BIG-IP).

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips