Firewall
guest@6admin.io:~$ ls ~/tags/firewall
Egress filtering, the control everyone skips
Securing outbound traffic: egress filtering, allow-lists and spotting a service talking to something it should not.
Inbound traffic: expose less and guard what is left
Securing inbound traffic: firewall, minimal exposure, reverse proxy and clean TLS termination.
Portknocking: automatic combination generation
Automatic portknocking sequence generation from the system date, with mandatory NTP and an encrypted USB key.