Read the following sections:

Using sudo to Gain root Privileges on page 428 of Sobell

sudoers: Configuring sudo on page 433 of Sobell

4. Working as ben, casey, and then max, test the modified sudoers file as

follows

a. First, change your effective UID to ben and verify your effective UID.

After testing as ben, repeat each of the steps in this section for casey and

max.

b. Use df to verify that the /boot filesystem is mounted.

c. Attempt to unmount /boot without using sudo.

d. Use sudo to unmount /boot.

e. Use df to verify that the /boot filesystem is no longer mounted.

f. Use sudo to mount /boot.

g. Ensure that ben, casey, and max cannot run other commands using sudo.

For example, while working as ben, use sudo to attempt to display the

/var/log/messages file.

h. Return to working with, and verify you are working with, an effective

UID of student.