Answers to Chapter Questions

Chapter Pre-Test

1.Linux can be used in the enterprise at every level, from the desktop, to the server.

2.Samba provides connectivity with windows-based PCs or servers by using the SMB protocol.

3.Linux can be used to install a firewall that can limit or prevent unauthorized access.

4.Linux supports e-mail through use of standards-based software such as Sendmail, which is based on the Simple Mail Transport Protocol (SMTP).

5.Linux supports the most popular Web server in use today, which is the Apache web server.

6.Linux can provide file and print services for the Mac OS with support for the Appletalk protocol.

7.Linux can provide every major service that is offered by other operating systems, which makes it an attractive alternative.

8.Linux is very competitive with rival operating systems in terms of cost, reliability, and efficiency, and is a viable choice in most situations.

9.Because drivers for hardware devices are created as they come out by mostly volunteer developers, sometimes Linux does not support very new technologies.

10.Linux offers many places to gather information about the services that it can run, including — but not limited to — the sites that maintain the service software, Linux.org and Linuxdocs.org, and the MAN pages for the service.

Assessment Questions

1.A. WordPerfect is a popular word processor that is available for both Microsoft and Linux operating systems. Microsoft Word has not been ported to Linux; Opera is a Web browser; and Domino is an e-mail server. See the sections “Word Processing” and “Spreadsheets and Databases” for more information.

2.D. Excel is a Microsoft Product that has not been ported to Linux. The others have all been created or ported to Linux. See the section “File servers” for more information.

3.C. The KDE-based Web browser is Konqueror. Netscape and Opera are excellent Web browsers, but they are not part of KDE; neither is Internet Explorer. See the section “ Web browsing” for more information.

4.D. MSN Instant Messenger is not available for Linux; the others are all available in some form for Linux. See the section “More, more, and more applications” for more information.

5.B. DNS provides name to IP mapping; DHCP supplies automatic addressing; WINS is a Microsoft service; UUCP is an old file transfer protocol. See the section “The Server and DNS” for more information.

6.A. SMTP is the most common protocol for an e-mail server. Sendmail is a software package that supports SMTP. SNMP is simple network management protocol, and X.400 is not the primary e-mail service in use today. See the section “Linux e-mail server” for more information.

7.B. The Samba software package provides for Microsoft SMB support in Linux so that Linux machines can connect to Microsoft network resources. NetBIOS is a Microsoft protocol; NFS is used to support UNIX; and DDP is used to support the MAC OS. See the section “File servers” for more information.

8.C. Squid provides the Proxy service, which caches and filters web traffic. E-mail is supported by sendmail; news is supplied by INN; and firewalls are created with ipchains and Netfilter. See the section “Proxy, news, and search servers” for more information.

9.D. NNTP protocol is used for news services. LeafNode and INN are examples of news servers, and Squid is a proxy server. See the section “Proxy, news, and search servers” for more information.

10.A. Dig is the common name of the service that provides searches on an intranet or domain. The others are all services not related to searching on an intranet or domain. See the section “Proxy, news, and search servers” for more information.

11.D. wu-ftpd is an example of a common FTP server application. Apache is a web server, Squid is a proxy server, and TFTP is actually a protocol used for connectionless FTP transfers. See the section “FTP servers” for more information.

12.A. ipchains is an example of the Linux firewall software that is built-in to the kernel. Netfilter is a separate firewall application, NAT is merely a Network Address Translation table, and stateful packet inspection is an advanced firewall filtering technique. See the section “Firewalls” for more information.

13.B. NAT stands for Network Address Translation. See the section “Firewalls” for more information.

14.C. Linux is least likely to provide excellent support for Fibre Channel because this is the newest hardware. See the section “Hardware compatibility” and “Comparing Linux with other operating systems” for more information.

15.A. HCL is where you should look first to learn if Linux supports a particular hardware device. SUNW is the stock ticker for Sun Microsystems; the MAN pages may have some hardware information, but they are usually used for software configuration and information; and finally, Linux.org does not support an extensive hardware list. See the section “Hardware compatibility” for more information.

16.A. The site www.apache.org is helpful for configuring the Apache Web server. The others do not support Web servers. See the section “A Linux Web server” for more information.

17.C. The following Web site can be used to gather information about creating a firewall: http://netfilter.filewatcher.org. The other Web sites don’t support firewall software; Squid is for proxy services, Leafnote is a news server; and Dig is a search server. See the section “Firewalls” for more information.

18.A. NIS is used with NFS to provide remote file access for UNIX systems. NAT is used to allow many IPs to use a single IP to access the Internet; NNTP is a news server protocol; and SMB allows the remote access of a windows system to Linux and Linux to windows. See the section “File servers” for more information.

19.A. MTA is the task that a Sendmail server provides, which is transferring mail from one network or host to another. MUA is a mail user agent; MDA is a mail delivery agent; and DDP is Datagram Delivery Protocol. See the section “Linux e-mail server” for more information.

20.C. TFTP is an example of a connection-less protocol for file transfer. The others are connection-oriented. See the section “FTP servers” for more information.

Scenarios

1.To create a Web server, you should install the Apache Web server. To provide better services for local users, add a Squid proxy server to cache Web pages to decrease the amount of traffic going to the Internet.

2.To protect the internal network from unauthorized users from an outside network, a firewall server should be installed. In order to share the Internet connection, the NAT service should be set up to allow all machines to connect to the Internet using one IP address.