Bug ID 431141: New active unit might drop connections due to rare server packet race window

Last Modified: Apr 10, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(all modules)

Known Affected Versions:
11.4.0, 11.4.1

Fixed In:
11.5.0, 11.4.1 HF6

Opened: Sep 19, 2013
Severity: 2-Critical


An established connection might be dropped after failover from a newly active unit. This occurs because of a small race window that exists while processing the arrival of consecutive packets.


An established connection drops after failover, and a new connection must be established.


This rare condition occurs on failover.


NA for FIX latency solution for ePVA to avoid the connection drop.

Fix Information

This release fixes a race window that occurred after a failover operation resulted in dropped connections on the new active unit.

Behavior Change