Bug ID 727266: ICMP monitors may be marked down if packet-filter is set to discard or reject

Last Modified: Apr 29, 2023

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

Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3,,,,,,,, 12.1.4,, 12.1.5,,,, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,,,,,,, 13.1.1,,,,, 13.1.3,,,,,,, 13.1.4,, 13.1.5,, 14.0.0,,,,,, 14.0.1,, 14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,,,,, 14.1.5,,,,, 15.0.0, 15.0.1,,,,

Opened: Jul 09, 2018

Severity: 4-Minor


ICMP monitors may incorrectly mark pool members down if packet filters are used


Monitors incorrectly mark the pool member down.


1. If an ICMP monitor is configured, as well as packet filters, and the default packet-filter action is Discard or Reject, and no rule exists to specifically allow the reply traffic, then the ICMP echo reply packets may be dropped, and the monitor will be marked down. 2. This can also be encountered by simply pinging the target from the BIG-IP command line.


Either add a packet filter rule specifically allowing the return traffic, change the default packet filter behaviour to 'accept', or use a different type (non ICMP) of monitor.

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips