Bug ID 643631: Serverside connections on virtual servers using VDI may become zombies.

Last Modified: Aug 19, 2026

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

Known Affected Versions:
11.5.3, 11.5.3 hf1, 11.5.3 hf2, 11.5.4, 11.5.4 hf1, 11.5.4 hf2, 11.5.4 hf3, 11.5.4 hf4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 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, 11.6.1, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 12.0.0, 12.0.0 hf1, 12.0.0 hf2, 12.0.0 hf3, 12.0.0 hf4, 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

Fixed In:
12.1.3, 11.6.3

Opened: Feb 07, 2017

Severity: 2-Critical

Related Article: K70938130

Symptoms

Listing connections with "tmsh show sys connection all-properties" (please be cautious executing this command as it could have performance impact) will show connections with only a server side whose age is greater than the configured idle timeout. As more zombie connections accumulate, the BIG-IP may run out of memory.

Impact

Zombie connections consume memory that cannot be reclaimed. Potential out-of-memory condition.

Conditions

APM provisioned and VDI (Virtual Desktop Infrastructure) is configured on the affected virtual.

Workaround

None.

Fix Information

Expired serverside connections are properly torn down.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips