# Linux Stuff ## Hardening 1. Automatic Updates (Non-prod only) 2. SSH Logins 3. Lockdown logins 4. Firewall ### Automatic Updates To do updates manually. Don't do this on Production servers because you should have better planning to upgrade you key servers. ``` apt update apt upgrade ``` Install a utility that will perform auto-upgrades ``` apt install unattended-upgrades ``` Configure the utility ``` dpkg-reconfigure --priority=low unattended-upgrades ``` ### SSH Logins ### Lockdown Logins Edit the following file in nano on the server: ``` sudo nano /etc/ssh/sshd_config ``` Make the following changes: 1. Change the **Port** to something other than 22 2. Uncomment **AddressFamily** 3. Change AddressFamily to **inet** 4. Change PermitRooLogin to **no** 5. Change PasswordAuthentication to **no** Save the file and restart the ssh service ``` sudo systemctl restart sshd ```