Bug ID 754143: TCP connection may hang after finished

Last Modified: Nov 04, 2019

Bug Tracker

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

Known Affected Versions:
14.1.0, 14.1.0.1

Fixed In:
15.0.0, 14.1.0.2

Opened: Dec 27, 2018
Severity: 2-Critical
Related AskF5 Article:
K45456231

Symptoms

TCP connections hang. Memory usage increases. TMM restarts. Numerous hanging connections reported similar to the following: -- config # tmsh show sys conn protocol tcp Sys::Connections 10.0.0.1:5854 10.0.0.250:80 any6.any any6.any tcp 449 (tmm: 0) none none 10.0.0.1:5847 10.0.0.250:80 any6.any any6.any tcp 449 (tmm: 0) none none 10.0.0.1:5890 10.0.0.250:80 any6.any any6.any tcp 449 (tmm: 0) none none 10.0.0.1:5855 10.0.0.250:80 any6.any any6.any tcp 449 (tmm: 0) none none 10.0.0.1:5891 10.0.0.250:80 any6.any any6.any tcp 449 (tmm: 0) none none

Impact

Those connections hang indefinitely (even past the idle timeout). Memory increases, eventually leading to a possible TMM out-of-memory condition, requiring a TMM restart. Traffic disrupted while tmm restarts.

Conditions

Pool member fails to respond with an ACK to BIG-IP system serverside FIN. The BIG-IP system serverside connection eventually times out, and the clientside connection is orphaned.

Workaround

None.

Fix Information

TCP connections no longer hang under these conditions.

Behavior Change