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

Last Modified: Apr 10, 2019

Bug Tracker

Affected Product:  See more info
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, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.2, 11.5.2 HF1, 11.5.3, 11.5.3 HF1, 11.5.3 HF2, 11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8

Fixed In:
12.0.0, 11.6.1, 11.5.4

Opened: Apr 09, 2015
Severity: 3-Major
Related AskF5 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