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, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 16.0.0, 16.0.0.1, 16.0.1

Fixed In:
16.1.0, 16.0.1.1, 15.1.2

Opened: Jun 12, 2020

Severity: 2-Critical

Symptoms

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

Impact

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

Conditions

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

Workaround

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 192.0.2.53:53: instead of this: RESOLV::lookup @/Common/my_dns_virtual use this: RESOLV::lookup @192.0.2.53

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips