Bug ID 517282: The DNS monitor may delay marking an object down or never mark it down

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.2.0, 11.2.1, 11.3.0, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.6.0, 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, 11.5.4

Opened: Apr 09, 2015

Severity: 3-Major

Related Article: K63316585

Symptoms

The DNS monitor may not mark an object down within the monitor timeout period or may never mark the object down.

Impact

The DNS monitor may not mark an object down within the monitor timeout period or may never mark the object down.

Conditions

A DNS monitor with no configured recv string and the monitor receives an ICMP error other than port unreachable.

Workaround

Supply an appropriate recv string to the monitor definition: tmsh modify ltm monitor dns mydns recv 10.1.1.1 Or add another monitor to the object: tmsh modify ltm pool dnspool monitor min 2 of { mydns gateway_icmp }

Fix Information

DNS monitor should mark server down when getting ICMP admin prohibited error. This is correct behavior.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips