Bug ID 916753: RESOLV::lookup returns empty string when querying against a local virtual server, and results in possible tmm core

Last Modified: Sep 13, 2023

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

Known Affected Versions:
15.1.0,,,,,, 15.1.1, 16.0.0,, 16.0.1

Fixed In:
16.1.0,, 15.1.2

Opened: Jun 12, 2020

Severity: 2-Critical


-- RESOLV::lookup returns an empty string. -- TMM might crash.


RESOLV::lookup does not return the expected result; tmm might crash. Traffic disrupted while tmm restarts.


An iRule runs RESOLV::lookup targeting the query toward a local virtual server. For instance: RESOLV::lookup @/Common/my_dns_virtual www.example.com


In the RESOLV::lookup command, replace the name of the virtual server with its IP address, or the IP address of an external DNS server. For instance, if /Common/my_dns_virtual has destination instead of this: RESOLV::lookup @/Common/my_dns_virtual use this: RESOLV::lookup @

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips