cat /dev/null > ~/.bash_history && history -c && exit

Depending on the server configuration, I’ve noticed at the end of the boot cycle Ubuntu throws this error:

cloud-init [1416]: Cloud-init v. 23.3.3-0ubuntu0~22.04.1 running ‘modules:config’

cloud-init [1453]: Cloud-init v. 23.3.3-0ubuntu0~22.04.1 running ‘modules:final’

cloud-init [1453]: Cloud-init v. 23.3.3-0ubuntu0~22.04.1 finished

Datasource DataSourceNone.

cloud-init [1453]: – cc_final_message.py[WARNING]: Used fallback datasource

You can disable this portion of the boot by typing:

sudo touch /etc/cloud/cloud-init.disabled

Remove current installation:

sudo apt remove update-notifier update-notifier-common

Install new:

sudo apt-get update -y
sudo apt-get install -y update-notifier-common

To help prevent/slow any brute force attacks while still having SSH enabled, its a good idea to change your SSH port from the default 22 to something at least 5 digits.

Install “netstat”:

sudo apt install net-tools

Check to see current SSH port:

sudo netstat -tulnp | grep ssh

Check to see current sshd_config configuration:

grep -i port /etc/ssh/sshd_config

Open the sshd_config and search for: “#Port 22”

sudoedit /etc/ssh/sshd_config

Uncomment and change the port number to your preference

Save sshd_config and restart SSH service:

sudo systemctl restart sshd

Confirm SSH daemon now listens to new port:

sudo netstat -tulpn | grep ssh

If necessary add new port to firewall:

sudo ufw allow 12345/tcp

Remove old ports:

sudo ufw status
sudo ufw status numbered
sudo ufw delete #