clear F5 network firewall event log

Disclaimer:

I'm probably treading in deep water now as I have virtually no experience with AFM, but try this?

Stop the syslog service
/etc/init.d/syslog-ng stop;
Remove the log
rm /var/log/[log file of your choosing (afm?)];
Start the syslog service
/etc/init.d/syslog-ng start;

/Patrik