In this hands-on project, you configure and test the netfilter/iptables utility. 1. Swi...

In this hands-on project, you configure and test the netfilter/iptables utility.

1. Switch to a command-line terminal (tty2) by pressing Ctrl+Alt+F2 and log in to the terminal using the user name of root and the password of secret.

2. At the command prompt, type iptables -L and press Enter. What is the default action for the three chains?

3. At the command prompt, type service httpd start and press Enter to ensure that the Apache Web server is running.

4. Switch to the gdm by pressing Ctrl+Alt+F1 or Ctrl+Alt+F7 and log in to the GNOME Desktop Environment as sample user one with a password of secret.

5. Open the Firefox Web browser, type in the location 127.0.0.1 and press Enter. Was your Web page displayed?

6. Switch back to your command-line terminal (tty2) by pressing Ctrl+Alt+F2.

7. At the command prompt, type iptables –P INPUT DROP and press Enter. What does this command do?

8. At the command prompt, type iptables -L and press Enter. What is the default action for the three chains?

9. Switch back to the GNOME Desktop Environment by pressing Ctrl+Alt+F1 or Ctrl+Alt+F7 and click the Reload button in Firefox. What message is displayed at the bottom of the Mozilla screen? Click the Stop button.

10. Switch back to your command-line terminal (tty2) by pressing Ctrl+Alt+F2.

11. At the command prompt, type iptables –A INPUT –s 127.0.0.1 –j ACCEPT and press Enter. What does this command do?

12. At the command prompt, type iptables -L and press Enter. Do you see your rule underneath the INPUT chain?

13. Switch back to the GNOME Desktop Environment by pressing Ctrl+Alt+F1 or Ctrl+Alt+F7 and click the Reload button in Firefox. Were you successful?Why? Log out of the GNOME Desktop Environment.

14. Switch back to your command-line terminal (tty2) by pressing Ctrl+Alt+F2.

15. At the command prompt, type iptables -F and press Enter. Next, type iptables –P INPUT ACCEPT at the command prompt and press Enter. What do these commands do? At the command prompt, type iptables -L and press Enter to verify that the default chains have been restored.

16. Type exit and press Enter to log out of your shell.