The following lines need to be added to the file /etc/rc.conf in order to take effect.
Please note that changes will not take effect until a system restart.
Prevent OS Fingerprinting tcp_drop_synfin=â€YESâ€
Prevent ICMP Redirect icmp_drop_redirect=â€YESâ€
Blackhole TCP Packets net.inet.tcp.blackhole=2
Blackhole UDP Packets net.inet.udp.blackhole=1
Route Cache Expire net.inet.ip.rtexpire=2
Minimum Route Cache Expire net.inet.ip.rtminexpire=2