Bug ID 836357: SIP MBLB incorrectly initiates new flow from virtual IP to client when existing flow is in FIN-wait2

Last Modified: May 29, 2024

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

Known Affected Versions:
12.1.1, 12.1.2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 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, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 13.1.3.2, 13.1.3.3, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1, 14.0.1.1, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.1.0, 15.1.0.1

Fixed In:
16.0.0, 15.1.0.2, 15.0.1.4, 14.1.2.5, 13.1.3.4, 12.1.5.2

Opened: Oct 10, 2019

Severity: 4-Minor

Symptoms

In MBLB/SIP, if the BIG-IP system attempts to send messages to the destination over a TCP connection that is in FIN-wait2 stage, instead of returning a failure and silently dropping the message, the BIG-IP system attempts to create a new TCP connection by sending a SYN. Eventually, the attempt fails and causes the connection to be aborted.

Impact

This causes the BIG-IP system to abort the flow that originates the message.

Conditions

-- This happens on MBLB/SIP deployment with TCP. -- There is message sent from the server to the BIG-IP system. -- The BIG-IP system forwards the message from the server-side to client-side. -- The destination flow (for the BIG-IP system to forward the message to) is controlled by 'node <ip> <port>' and 'snat <ip> <port>' iRules command. -- The destination flow is in the FIN-wait2 stage.

Workaround

None.

Fix Information

SIP MBLB correctly initiates a new flow from a virtual IP to the client when an existing flow is in the FIN-wait2 stage.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips