Bug ID 630306: TMM crash in DNS processing on UDP virtual server with no available pool members

Last Modified: Sep 13, 2023

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

Fixed In:
13.0.0, 12.1.2 HF1

Opened: Nov 25, 2016

Severity: 2-Critical

Related Article: K20455313

Symptoms

TMM crash when processing requests to a DNS virtual server.

Impact

Traffic disrupted while tmm restarts.

Conditions

The issue can occur if a UDP DNS virtual receives a request when no pool members are available to service the request and a DNS iRule is suspended due to previous requests.

Workaround

Mitigation is to ensure at least one pool member is available whenever the DNS virtual is processing traffic, or to avoid iRule commands that can suspend processing. Ensure datagram LB mode is enabled on UDP DNS virtuals.

Fix Information

This release prevents a crash in DNS processing on UDP virtual server with no available pool members.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips