Assignment

Write down any assumptions you make if a question is not clear.

1. Mail route.

The journey an email might take from your computer to your friend's computer has many steps in it. Describe four things that might go wrong with the email delivery system that could stop your email from getting through.

2. Spam.

In an effort to reduce spam, the government is thinking of setting up a post-office system for delivering email. All clients would send outgoing mail to their nearest post-office computer managed by the government. This computer will relay the mail through other post-office machines to its destination. The email will be inspected along the way to detect and remove spam. Incoming email would only be received from the neighborhood post-office computer. Describe any problems you see with this plan.

3. Web site account.

You have a few pages on your web site that you only want certain people to see. You are considering either simply password protecting each page and distributing the password to people who need it, or creating a site in which members can login after setting up an account to see the pages. Which of these two approaches will you pick and why?

4. Public and Private.

Your boss wants you to establish a web presence for the company. Portions of your new web site should be accessed only by people in your company, while the rest is open to the public. You are considering two alternatives:

(a) have the sites on two machines, a public site on a computer in the DMZ, and a privatesite on a computer in the internal network

(b) having two virtual sites, one public and the other private, on a computer that acts asthe router between your DMZ and the internal network

Choose the best plan and give at least two reasons why you chose it.

5. Big Data Source.

Assume you want to distribute a large quantity of large files to the public.
(a) Give a reason why you would want to do this distribution through a web site.
(b) Give a reason why you would want to do this distribution through an ftp site.
(c) Which technique would you choose?

6. Secure ftp.

Currently there is a secure channel version for web sites using https, but there is not a corresponding secure channel version for ftp sites.

(a) Why would you need a secure channel for an ftp interaction?
(b) If it is needed, why hasn't anybody ever developed such a protocol?

7. On the road.

One of your salesmen is going on a trip and taking a company laptop with him. He needs to have access to one of the company databases, but you can't afford to have someone from outside the company gain access to it. You are trying to choose between putting a copy of the database on the laptop and encrypting the hard drive, or linking the laptop into your network through a VPN to gain access. Discuss the relative merits of these two plans.

8. Perfection.

Your friend says that he has developed a new encryption algorithm that cannot be broken and is very efficient, and that the government should adopt it as a replacement for AES right now. How should your friend proceed to try and accomplish his goal?

9. Firewall types.

Assume that a routing device contains a packet filter firewall within it, but you don't know if the firewall is stateful or not. Describe two types of packets you could try to send through the firewall that would allow you to determine which type it is.

10. Pick one.

We talked about several types of software you might run on a host to check for malware. Assume you can only install one of these on your system to keep it safe. Which one would you choose and why?

11. User troubles.

You know that regardless of all the security precautions you put in place on the system, your users can still be the weakest link. You want to remind them not to do stupid things, so you plan on sending an email with the top three mistakes they should avoid making in order to insure the best level of security on the system. What three mistakes would you include in this email?

12. Slow down.

One of your employees is complaining that his system is running too slow. Describe two troubleshooting steps you would take to try and find the reason for his computer's slowness.

13. The cloud.

Your boss has heard all about cloud computing and wants to shift as many of the services handled by your local server to the cloud as possible.

(a) Name a service you think would work well if shifted to the cloud and describe why.
(b) Name a service you know would not work well if shifted to the cloud and describe why.

14. Printer.

Your friend wants to design a new super printer by attaching a Raspberry Pi to a normal wireless printer and running a CUPS server on it. It won't raise the price of the printer that much, and all of the features of a print server can be incorporated into the device.

(a) Point out any problems you see with your friend's plan to get rich with this new deviceby hopefully eliminating the need for printer servers.

(b) You have an alternate plan - going paperless by eliminating all printers and just storingpdf files in a central repository. How can you convince your friend to support your plan rather than his?

15. Merger.

Assume your company, which has a Unix only environment managed by you and your staff, is being merged with another company that has an all Windows environment. A plan needs to be developed for how to integrate the computing resources (printers, file systems, user accounts) of each company as much as seems reasonable. Only the IT staff that comes up with the best plan is going to be maintained. Outline a way to do this integration that will keep you and your staff employed and still have a highly functional system.

16. Scripting.

You've gotten a small look at what shell scripting might be like.

(a) Describe two automation tasks you believe would be ideally handled by writing a bashscript to do them.

(b) Describe an administrative task you think might be too complicated for a bash scriptand would require using a more general language like Python.