CIT 174

Week 7
Chapter 7 Review Questions

1.) Name three types of remote connectivity supported by Linux and explain why one is preferred over the other two. The three programs listed are Telnet, r-utilities, and SSH. SSH is the preferred way to connect because the transferred data is encrypted.

2.) One advantage of Telnet is that (c) it can be used on many different platforms, including Linux and Windows.

3.) Name three utilities that are part of the r-utilities suite and explain what each does. The first is rsh that allows you to execute a program, rcp that allows you to copy files, and rwho that lists the users that are logged on to the remote computer.

4.) The rcp program is able to copy files between (d) any two computers that are configure to use the r-utilities programs.

5.) Name the three types of authentication that SSH can use to connect to a remote system. Which is preferred as the most secure? SSH can use r-utilities, user passwords, or public key encrypting, the later is the preferred method.

6.) Which utility is used to prepare a set of keys needed to use public key encryption within SSH? (b) ssh-keygen.

7.) Why might you need to use the -l option with the ssh command? If you have a user account on the server this option only prompts you for your password.

8.) If you use the ssh command without first creating and storing a key pair on the remote host (a) you are prompted for a password to aid authentication.

9.) If you have installed and configured r-utilities, then including a host and user name in your .rhosts file allows a person using the rcp command on another host to (a) copy files to or from your home directory without entering a password.

10.) SSH is commonly used in place of Telnet because (a) SSH provides a secure communications channel that is much more immune to security attacks.

11.) When using Telnet you might refer to VT100 because it is (c) the most commonly used terminal emulation standard.

12.) Telnet is considered dangerous because (b) It transmits data--including passwords--without encrypting them, so anyone on the network can see them by using special software.

13.) When using the wget command, you should include the http:// designation to download a Web page so that (a) the program knows which protocol to use when accessing the server.

14.) Suppose you want to mirror a Web site to your local computer in order to study the information it contains. You intend to update the mirror once each month to view changes in the Web pages on the site. You are concerned that the Web site administrator will block access if he realizes you are mirroring the entire site instead of using a regular browser to access it. In order to reduce the chance that the wget program creates suspicion, you can (c) use the --random-wait option with wget.

15.) The rsync program is best suited for (a) synchronizing collections of files such as software development files.

16.) On a publicly available anonymous FTP server, the first level subdirectory that you should go to when locating files to download is virtually always (d) /pub.

17.) A graphical FTP client can be more convenient than a text-mode FTP client such as ncftp because (b) the graphical program lets you see lists of files locally and remotely and drag and drop multiple files between systems.

18.) The ncftp package includes a utility that is similar in functionality to wget. This utility is called (a) ncftpget.

19.) If an IP address is not assigned explicitly when networking is configured, one must be obtained automatically from a server on the network using (a) DHCP.

20.) The process of resolving a domain name (b) determines the IP address associated with that domain name by contacting a DNS server.

21.) ping is used to test networking connections by (a) trying to contact systems that are progressively further from your host to see if any networking problems occur.

22.) traceroute is a useful troubleshooting tool because (c) it reports each router that a packet passes through to a remote computer, along with the time needed to reach that router.

23.) If you cannot ping a host on your local network using that system's IP address, you probably wouldn't bother checking (a) whether you could ping a host on the Internet.

24.) Which of the following is not included in the output of the traceroute command? (d) The size of the test packet sent by traceroute.

25.) A DHCP server can provide what information to a host on the network in response to a DHCP client request? (b) an IP address, a network mask, a gateway address, a DNS server address, and a host name, among other things.