Bug ID 693244: BIG-IP not sending RST for SYN,ACK packets when ASM is provisioned

Last Modified: May 07, 2019

Bug Tracker

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

Known Affected Versions:
13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 14.0.0, 14.0.0.1, 14.0.0.2

Fixed In:
14.1.0, 14.0.0.3, 13.1.0.6

Opened: Nov 07, 2017
Severity: 3-Major

Symptoms

BIG-IP silently drop the serverside TCP flow, when it receives a client-side reset and the server-side flow is still in the SYN-SENT state.

Impact

Since serverside pool member does not receive the RST, it remains in SYN-RECEIVED state until it runs out of syn retransmissions and eventually, due to timeout, it returns to LISTEN state.

Conditions

BIG-IP receives a client-side reset when client-side TCP flow is in ESTABLISHED state and server-side TCP flow is in SYN-SENT state, serverside flow is silently dropped.

Workaround

None

Fix Information

BIG-IP resets serverside TCP flow with RST when it receives a client-side reset and the server-side flow is still in the SYN-SENT state.

Behavior Change