BugZero | F5 BugID 1326797 - The Pool State of an offline pool with one or more...

F5 - Defect ID: 1326797

The Pool State of an offline pool with one or more user-disabled pool members depends on which pool member was marked down last by its monitor (non-deterministic behaviour)

F5 - Defect ID: 1326797

The Pool State of an offline pool with one or more user-disabled pool members depends on which pool member was marked down last by its monitor (non-deterministic behaviour)

Last updated on May 5th, 2026

BugZero Risk Score
6.2 Medium

Overall: 6.2

Severity: 6.4

Community: 4.2

Lifecycle: 10.0

What is the BugZero Risk Score?

F5 Integration

Learn more about where this data comes from

F5 Integration

Learn more

Bug Scrub Advisor

Streamline upgrades with automated vendor bug scrubs

Bug Scrub Advisor

Learn more

BugZero Enterprise

Wish you caught this bug sooner? Get proactive today.

BugZero Enterprise

Learn more

Bug Details

Priority: 4-Minor
Status: Resolved
Impact Category: Local Traffic Manager
Views: 13

Description

Symptoms

When you have two or more pool members with one pool member being administratively disabled and the other(s) being enabled, and all pool members are marked down by their monitor, the pool status depends on which pool member was marked down last. Specifically: - the disabled pool member is marked down by the monitor last - pool is in "offline/disabled-by-parent" state - one of the enabled pool members are marked down by monitor last - pool is in "offline/enabled" state

Impact

When all the pool members are marked down by their monitors, the State of the pool depends on which pool member was last marked down by its monitor.

Conditions

- LTM pool configured with two or more pool members - One pool member administratively disabled and the other(s) enabled - All pool members marked down by their monitors

Workaround

None

Fix Information

None

Change history

2026-05-05 Added: 15.1.10.7, 15.1.10.8, 16.1.6.1, 17.1.3, 17.1.3.1, 17.1.3.2, 17.5.1.2, 17.5.1.3, 17.5.1.4, 17.5.1.5, 17.5.1.6

2026-03-27 Added: 15.1.10.7, 15.1.10.8, 16.1.6.1, 17.1.3, 17.1.3.1, 17.5.1.2, 17.5.1.3, 17.5.1.4, 17.5.1.5

2025-12-31 Added: 15.1.10.7, 15.1.10.8, 16.1.6.1, 17.1.3, 17.5.1.2, 17.5.1.3

2025-11-15 Added: 15.1.10.7, 15.1.10.8, 16.1.6.1, 17.1.3, 17.5.1.2, 17.5.1.3

2025-10-19 Added: 15.1.10.7, 15.1.10.8, 16.1.6.1, 17.1.3, 17.5.1.2, 17.5.1.3

2025-10-15 Added: 17.1.3, 17.5.1.2, 17.5.1.3

2025-10-07 Added: 17.5.1.2

2025-06-28 Added: 15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6, 17.0.0, 17.0.0.1, 17.0.0.2, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.5.0, 17.5.1

Relevant Products

Click on a version to see all relevant bugs

Affected versions:15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 15.1.10.7, 15.1.10.8, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6, 16.1.6.1, 17.0.0, 17.0.0.1, 17.0.0.2, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.1.3, 17.1.3.1, 17.1.3.2, 17.5.0, 17.5.1, 17.5.1.2, 17.5.1.3, 17.5.1.4, 17.5.1.5, 17.5.1.6

Fixed versions: No known fixed versions

Relevant Products

Click on a version to see all relevant bugs

Fixed versions: No known fixed versions

Top F5 Defects

9.7Defect ID: 1505789
VPN connection fails with Edge client 7.2.4.6 with error "Network is vulnerable"
9.6Defect ID: 2141125
Multicast traffic is dropped with incorrect VLAN tagging
9.4Defect ID: 2292013
Admin users cannot create or view virtual servers and other objects in non-Common partitions in TMUI
9.4Defect ID: 1785385
Intermittent traffic failures when tenant is running BIG-IP v17.1.2 or above and host is on version prior to F5OS-A 1.8.0 or F5OS-C 1.8.0
9.4Defect ID: 2291757
Cannot login through ssh or console after upgrading to 17.5.1.6

Ready to prevent the next vendor outage?

Get a demo

F5 - Defect ID: 1326797

The Pool State of an offline pool with one or more user-disabled pool members depends on which pool member was marked down last by its monitor (non-deterministic behaviour)

F5 - Defect ID: 1326797

The Pool State of an offline pool with one or more user-disabled pool members depends on which pool member was marked down last by its monitor (non-deterministic behaviour)

Last updated on May 5th, 2026

BugZero Risk Score6.2 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Top F5 Defects

Ready to prevent the next vendor outage?

Links

BugZero Risk Score
6.2 Medium