Bug ID 1040277: Suspected syslog-ng issue which caused silent reboot of a system

Last Modified: Sep 23, 2021

Bug Tracker

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

Known Affected Versions:
13.1.0,,,,,,,,, 13.1.1,,,,, 13.1.3,,,,,,, 13.1.4,, 14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4

Opened: Aug 12, 2021
Severity: 3-Major


A syslog-ng issue with remote logging to an invalid remote syslog server may lead to unexpected reboot. The BIG-IP may unexpectedly reboot after a host watchdog timeout when syslog-ng gets hung up. This happens at the time of the last 'Syslog connection broken' in /var/log/messages before reboot. That message will appear without a preceding 'Syslog connection established' just before it with same timestamp. At this time syslog-ng typically spins, using near 100% CPU.


Very rarely syslog-ng hangs in a non-functional state. Sometimes, this may lead to an unexpected reboot of BIG-IP. Loss of logs before restart and traffic disrupted while BIG-IP restarts.


Invalid syslog-ng server configuration or broken connection from BIG-IP toward configured syslog-ng remote server.


Ensure syslog-ng server configuration is valid, and that the server is reachable.

Fix Information


Behavior Change