Question 1

The web administrator of your organisation needs to login remotely to the machine that is running the organisation's public web site.
You tell her that the only way to login is via The Secure Shell|which she knows nothing about! Assuming she is logging in via a
Linux box write a help document for her containing the following

a. A short introduction to SSH, explaining why it is the preferred way of logging into a remote machine|this explanation will need to discuss symmetric and asymmetric key encryption.

b. A discussion of the contents of the le ~/.ssh/known_hosts. Your discussion should include (but not be limitted to):

how the le is populated,  how the keys in the le are used by SSH,  a discussion of \man-in-the-middle" attacks,  why the hostnames in the le are \hashed", and how individual keys can be deleted by ssh-keygen.

c.  A description how to congure access so that no passwords are needed|that is by using user asymmetric keys. This will require

a discussion (with examples) of the command ssh-keygen, the le ~/.ssh/authorized_keys, passphrase protected keys and the commands ssh-agent and ssh-add.

Notes:

a. Any technical term used must be explained.

b. Your virtual Debian has the SSH dmon installed and run-ning by default|so you can SSH to it from the host system or from a second virtual machine.

c. Your virtual machine has two network interfaces congured|a host only interface and a NAT interface. To bring the host only network \up" study the man pages interfaces(5), ifup(8) and ifdown(8).

d. You must show the relevant changes/parts of any les discussed.

e. This is a help document so you must explain (in your own words) the purpose of every le and command mentioned (plus any command line options).

Be very clear which key (public or private) is stored on which machine (remote or local)

g. Port forwarding, SSH tunnels and rewalls need not be discussed| they will be covered later in the course.

Question 2
a.  In about a page explain in your own words what a Logical Volume Manager is, its purpose and why it is useful.
b.  Illustrate your explanation by using the Linux Log- ical Volume Manager to combine the two spare disks available on the Virtual Debian distribution. Combine the two disks into one logical volume. Format the new logical disk and modify the /etc/fstab le to mount the new disk at boot.
c.  Document and explain in your own words the purpose of every command you use (plus any command line options) and any conguration les or scripts you modify or create.

Notes:

a. Be certain to explain the meaning of any tehnical terms you may use|for example, what is a \physical volume", a \volume group", &c.
b. Make use of the utilities pvdisplay, vgdisplay, &c. to show the results of commands and that they have worked.

Question 3

A user comes to you requesting that you create and implement a backup policy for his desktop machine. What he wants, is to be able to place a blank DVD in his Single-Sided DVD-burner at the end of the working day on a Friday and have all the les he has been working on for the week backed up automatically that evening to the DVD!

After a bit more questioning you nd out that:


He frequently creates/deletes and changes les on a daily basis.
 He wants to be able to recover les for any given day.
 He only wants his home directory backed up.
 His home directory contains about 2Gbytes of data.
 His desktop machine has a spare disk (mounted as /spare) that has plenty of free space for temporary storage.

Tasks that need to be done:

4a.  Using the information above design a backup policy. Give a detailed description and justication of your backup-policy.
b. Using tar, a shell script or scripts and a crontab le implement your backup policy.
c.  Document and explain in your own words the purpose of every command you use (plus any command line options) and any conguration les or scripts you modify or create.

Attachment:- Assignment.pdf