Bug ID 700527: cmp-hash change can cause repeated iRule DNS-lookup hang

Last Modified: Sep 13, 2023

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

Known Affected Versions:
12.1.2, 12.1.3,, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,

Fixed In:

Opened: Jan 03, 2018

Severity: 3-Major


An iRule that uses RESOLV::lookup can hang repeatedly when cmp-hash configuration is changed.


The iRule call can hang repeatedly.


-- iRule is in the middle of a call to RESOLV::lookup. -- A change is made to VLAN cmp-hash configuration.


Restart the TMM. This will interrupt client traffic while TMM restarts.

Fix Information

The iRule connection is reestablished when the pending query expires, so subsequent RESOLV::lookup calls do not hang per TMM.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips