Bug ID 1819777: In-tmm TCP monitor with no RCV and RCVdisable string might lead to a crash

Last Modified: Mar 31, 2025

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

Known Affected Versions:
16.1.5, 16.1.5.1, 16.1.5.2, 17.1.2, 17.1.2.1, 17.5.0

Opened: Feb 18, 2025

Severity: 2-Critical

Symptoms

In-tmm TCP monitor with no RCV and RCVdisable string might lead to a crash.

Impact

Traffic disrupted while tmm restarts.

Conditions

This happens when TCP in-tmm monitor is configured without any matching disable/enable string ltm monitor tcp TCP { adaptive disabled defaults-from tcp interval 5 ip-dscp 0 recv none <<<< ! recv-disable none <<<< ! send "GET /check HTTP/1.0\r\n\r\n" time-until-up 0 timeout 16 } Bigd monitoring is not affected.

Workaround

- Disable in-tmm monitoring. - OR, configure in-tmm TCP monitor with any string match.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips