Bug ID 1133557: Identifying DNS server BIG-IP is querying to resolve LTM node FQDN name

Last Modified: May 29, 2024

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

Known Affected Versions:
13.1.0,,,,,,,,, 13.1.1,,,,, 13.1.3,,,,,,, 13.1.4,, 13.1.5,, 14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,,,,, 14.1.5,,,,,, 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,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,,,,, 17.0.0,,, 17.1.0,,,

Fixed In:
17.1.1, 16.1.4, 15.1.10

Opened: Aug 03, 2022

Severity: 4-Minor


When the BIG-IP (dynconfd process) is querying a DNS server, dynconfd log messages do not identify which server it is sending the request to. When more than one DNS server is used and there is a problem communicating with one of them, it might be difficult for system admin to identify the problematic DNS server.


There are no show commands or log displaying which DNS is currently being used to resolve LTM node using FQDN. Problems with communications between the BIG-IP and DNS server(s) may be more difficult to diagnose without this information.


This occurs when using FQDN nodes or pool members on affected BIG-IP versions.


You can confirm which DNS server is being queried by monitoring DNS query traffic between the BIG-IP and DNS server(s).

Fix Information

The DNS server being queried to resolve LTM node FQDN names is now logged by default in the /var/log/dynconfd.log file.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips