Bug ID 2132165: TCP connection fail when tm.tcpstopblindinjection is enabled

Last Modified: Dec 11, 2025

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

Known Affected Versions:
17.1.2.2, 17.1.3, 17.5.0, 17.5.1, 17.5.1.2, 17.5.1.3

Fixed In:
21.0.0

Opened: Oct 16, 2025

Severity: 2-Critical

Symptoms

Connections fail through virtual servers as the server's initial data is dropped.

Impact

Connections fail.

Conditions

- DB key tm.tcpstopblindinjection is enabled - Virtual server for protocol where server speaks first (e.g. SMTP, SSH/SFTP, FTP)

Workaround

Disable the DB key sys db tm.tcpstopblindinjection

Fix Information

Improved handling of sys db tm.tcpstopblindinjection

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips