Sample questions for Exam #2

1. Explain how NFS uses a UID to grant permissions to files when mounting. Discuss any security problems, if any, associated with this method and their solution(s).

2. Explain why routers are "intelligent" switches

3. What are the different types of DNS name servers and how are they different?

4. What is a namespace? Give 3 examples of a namespace. What is the difference between a flat and hierarchical namespace?

5. Explain the difference between a recursive vs a nonrecursive server, and how each is used in the resolution process.

6. What are some of the disadvantages to NFS servers being stateless?

7. You've just created a folder with family pictures that you'd like to share with your family on your recently configured NFS server. Which file would you edit (or create) to accomplish this?

8. What is the difference between and authoritative and a caching server? Why not just use authoritative name servers?

9. Which of the following contains the NFS mounts for boot time?
   a./bin/mount.conf
   b./etc/fstab
   c./bin/NFSboot
   d./etc/exports
   

10. While running grub, what commands should entered to reset the master boot record to it's original configuration?

11. Describe the difference between a DNS PTR record and a CNAME record.

12. What are some preventive measures you can take while maintaining data centers?

13. List 4 types of namespace policies a SA should have and briefly describe what they are for.

14. What are the components of a URL address? Why isn't the port address of the service requested normally not included in the URL?

15. What are the four components of the e-mail system?

16. From our first project, what are the steps taken to modify your grub file to set up an .iso of another operating system?

17. Why are process of elimination and successive refinement not always the best solution to solving a problem?

18. What is the relationship between BIND and 'named'?

19. What programs might a typical email message pass through as one unix/linux user emails another and what do they do?

20. What are some important factors to consider when scheduling maintenance windows?

21. Write a simple zone file for domain studentgets100.com with IP address of local host with hosts "yes", and "ofcourse".

22. What version of GRUB does CentOS 6.2 utilize by default?

23. What should you do to provide a 'Truly robust DNS environment' and why?

1. What is an advantage of using centralization with server hardware?

2. What is the account name used for a "squashed" root user on a NFS Server?

3. Why is it important not to use vendor-installed operating system configurations?

4. Imagine your machine is on a network that has no working DNS or NIS, and your /etc/fstab is configured to mount filesystems from other machines using their DNS names. You know what IPs correspond to the entries in the /etc/fstab. How can you make the filesystems mount normally without changing your /etc/fstab?

5. What is the purpose of the command netstat?

6. What DNS method can be used by a machine to reduce DNS load? Explain.

7. What is the difference between TCP and UDP, and explain where one might be more appropriate than the other.

8. Why are root and top-level domain servers nonrecursive?

9. What are the benefits and detriments of a caching DNS server?

10. What is the name of at least one email delivery agent that we have gone over in class or in the readings?

11. What is the daemon that manages other daemons?

12. What is CIDR and what notation is used for CIDR?

13. What are two advantages that virtualization has over dual-booting?

14. T/F. If Bob and Mary share the same UID on two separate clients, they will have access to each other's NFS files?

15. True/False : the email address used in the from address part of an email must be the same as the email address used in the MTA/SMTP handshake.

16. As a system administrator, it may be important to block web access to some sites. How could this be accomplished using a proxy cache? Give an example to block all access to sites within the google.com domain.

17. What is wrong with this routing table?

    127.0.0.0        255.0.0.0        127.0.0.1        127.0.0.1        1
    205.217.146.0    255.255.255.0    205.217.146.200  205.217.146.200  1
    205.217.146.200  255.255.255.255  127.0.0.1        127.0.0.1        1
    205.217.146.255  255.255.255.255  205.217.146.200  205.217.146.200  1
    224.0.0.0        224.0.0.0        205.217.146.200  205.217.146.200  1
    255.255.255.255  255.255.255.255  205.217.146.200  205.217.146.200  1
    

18. Suppose a user has trouble accessing a website hosted on a name-based virtual host. How could this occur?

19. How does DNS solve scalability problems?

20. What are some of the security problems associated with NFS and how can these issues be avoided?

21. Give the path of the sendmail configuration file which can be modified.

22. Compare and Contrast NFS, Samba, and AFS

23. Explain how the DNS A and PTR records can provide a level of authentication.

24. The following commands are executed, in the following order:

    touch tmp1
    ln tmp1 tmp2
    ln -s tmp1 tmp3
    ln -s tmp2 tmp4
    rm tmp1
    

    What will be the state of the files (tmp1, tmp2, tmp3, tmp4)?

25. Describe the 5 network layers.

26. What is sendmail's configuration file?

27. What is DHCP and how does it work?

28. What are the advantages of CIDR (Classless Inter-Domain Routing)?

29. What steps must be taken to use a CGI script in Apache?

30. Why is it necessary for you to update the /etc/resolv.conf file each time you boot up your sandbox drive in order for it's associated service to function correctly?

31. What does the command 'netstat -rn' do? What are at least 2 other uses for the netstat command?

32. What are the advantages and disadvantages of automounting an NFS?

33. What are some advantages to having a local proxy server on your network?

34. If a packet of size 576 encounters a router with an MTU of 1500, which of the following would occur?
    a) The packet would go through an IP fragmentation
    b) There will be many acknowledgments being sent and handled due to the data to header ratio
    c) The packet is sent back to the sender
    d) None of the above
    

35. What is NFS's no_root_squash export option and why can it be dangerous?

36. How are the client mount points and the exported file systems tracked on the server?

37. Name at least 4 Top-Level Domains in the U.S. and what they are used for; Name at least 3 types of records found in a zone file and what they are for.

38. With NFS, what is typically used to prevent users with root access on a client from gaining access to any file? How does it work?

39. What are the 5 network layers and what do those layers contain?

40. What are some advantages of using a caching proxy server?