For this lab, you need a clean snapshot of your Ubuntu virtual machine:

1. Restore your Ubuntu virtual machine to a clean snapshot to clear out any firewall configurations that you created previously. Verify with the commands:

        sudo ufw status
        sudo iptables -L

You should see no rules listed for iptables, and the ufw status should be inactive.

2. Install the nftables package:

        sudo apt install nftables

3. List the tables, which should give you no output. Load the default configuration file, and list both the tables and the rules:

        sudo nft list tables
        sudo nft -f /etc/nftables.conf
        sudo nft list tables
        sudo nft list table inet filter

4. Make a backup copy of the nftables configuration file:

        sudo cp /etc/nftables.conf /etc/nftables.conf.bak

5. Open the original /etc/nftables.conf file in your text editor. Just before the tcp dport . . . accept line, insert this line:

        tcp dport ssh ip saddr { 192.168.0.7, 192.168.0.10 } drop

Save the file and exit the text editor.

6. Reload the configuration and view the results:

        sudo nft list tables
        sudo nft -f /etc/nftables.conf
        sudo nft list tables
        sudo nft list table inet filter

7. End of lab.