Bug ID 1074465: TMM SIGSEGV crash

Last Modified: Feb 14, 2024

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

Known Affected Versions:,,, 14.1.5

Fixed In:

Opened: Jan 20, 2022

Severity: 3-Major


If an error occurs while deleting a hardware SYN cookie Neuron rule, TMM may crash. Possible (but not required) symptoms include TMM logs before the crash like: neuron_client_send_data: Error: mds_conn_send_xbuf failed neuron_client_send_req: neuron_client_send_data failed: ERR_REJECT hudproxy_neuron_client_closed_cb: Neuron client connection terminated


Traffic disrupted while tmm restarts.


-- Platforms with Neuron/TCAM support (BIG-IP iSeries)


On HSB platforms it is possible to disable the Neuron SYN cookie feature by the 'HSBE::syncookie_neuron_enabled 0' Tcl command in /config/tmm_init.tcl. However, this would prevent full hardware SYN cookie protection for wildcard or subnet virtual servers.

Fix Information

Error handling during Neuron rule deletion is fixed.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips