Bug ID 749774: EDNS0 client subnet behavior inconsistent when DNS Caching is enabled

Last Modified: Dec 18, 2024

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

Known Affected Versions:
11.5.5, 11.5.6, 11.5.7, 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, 12.0.0, 12.0.0 HF1, 12.0.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 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, 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, 14.1.0, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6

Fixed In:
15.0.0, 14.1.0.1, 14.0.0.4, 13.1.1.4, 12.1.4, 11.6.3.4, 11.5.8

Opened: Nov 14, 2018

Severity: 3-Major

Symptoms

When EDNS0 client subnet information is included in a DNS request, and DNS caching is enabled, the responses differ in their inclusion of EDNS0 client subnet information based on whether the response was supplied by the cache or not.

Impact

Inconsistent behavior.

Conditions

This occurs when EDNS0 client subnet information is included in a DNS request, and DNS caching is enabled.

Workaround

To allow consistent processing of any EDNS0 queries with ECS information, use a DNS profile where DNS caching is disabled by default, and selectively use the DNS cache only for non-EDNS0 queries.

Fix Information

In this release, responses are now consistent when caching is enabled. When DNS cache is enabled, EDNS0 EDNS Client Subnet (ECS) information is removed from the DNS query as it is not supported

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips