Bug ID 446526: TCP virtual server/UDP virtual server without datagram-LB mode enabled running DNS cache and suspending iRules might cause TMM crash.

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.2.1, 11.3.0, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:
12.0.0, 11.6.1

Opened: Jan 28, 2014

Severity: 3-Major

Related Article: K15360

Symptoms

When a TCP virtual server, or a UDP virtual server without datagram-LB mode enabled, runs an iRule which suspends itself, and the traffic that virtual server is handling is destined for the DNS cache, subsequent responses attempting to execute an iRule crash TMM because the first response is suspended. Those subsequent responses should be queued before attempting to execute the iRule.

Impact

Traffic disrupted while tmm restarts.

Conditions

Configuration contains TCP virtual server, or a UDP virtual server without datagram-LB mode enabled running DNS cache and suspending iRules or there is iRule execution error.

Workaround

Enable datagram-LB mode on the UDP profile. There is no workaround in the case of TCP.

Fix Information

TMM no longer restarts when configuration contains TCP virtual server, or a UDP virtual server without datagram-LB mode enabled running DNS cache and suspending iRules.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips