Study Guide - Chap2: Intro to Services

Question 1

2- A ________ runs in the background and listens for client connection requests for a single application.

• Daemon
• Super‐server
• Shell
• Graphical desktop

Answer 1

Daemon

A daemon is a single application that runs in background listening for client connection requests, so option A is the correct answer. A super‐server listens for more than one application, so option B doesn’t apply. The shell doesn’t listen for network connections; it launches applications interactively, so option C is incorrect. The graphical desktop also allows you to launch applications, but it doesn’t listen for client connection requests, so option D is incorrect.

Question 2

3- Which open source database provided fast performance and became a popular choice for web applications?

• MongoDB
• PostgreSQL
• MySQL
• NoSQL

Answer 2

MySQL

When first released, the MySQL database server focused on speed, making it a popular choice for high‐volume Internet web applications, so option C is correct. The MongoDB database server provides object‐oriented database features but doesn’t focus on performance, so option A is incorrect. The PostgreSQL database focused on implementing fancy database features instead of speed, so option B is incorrect. NoSQL is a database storage method that incorporates object‐oriented data records and is not a database server package itself, so option D is incorrect.

Question 3

4- How does a server know what client request is sent to which application daemon?

• IP addresses
• Ports
• Ethernet addresses
• Services

Answer 3

Ports

Linux services listen on well‐known ports for requests from clients, so option B is correct. A server normally has a single IP address to support multiple applications, so option A is incorrect. The server also normally has only a single Ethernet address, so option C is incorrect. The clients can’t launch individual services on the server, so option D is incorrect.

Question 4

5- What popular open source web servers can also perform as a load balancer?

• nginX
• Apache
• PostgreSQL
• Lighthttpd

Answer 4

nginX

The nginX web server can serve as a load balancer and send client requests to multiple backend web servers, so option A is correct. The Apache and lighthttpd web servers don’t support this feature, so options B and D are incorrect. The PostgreSQL server is a database and not a web server, so option C is incorrect.

Question 5

6- What format does MongoDB use to store data elements in the database?

• Relational
• YaML
• JSON
• Encrypted

Answer 5

** JSON**

The MongoDB database server uses the JSON format for storing data records. The relational database is a type of database system and not a method for storing data, so option A is incorrect. YaML is a plaintext method for creating configuration files, but it is not used in MongoDB for storing data, so option B is incorrect. The MongoDB data is not normally encrypted, so option D is also incorrect.

Question 6

YaML

Answer 6

• YAML Ain’t Markup Language” or sometimes “Yet Another Markup Language
• YAML is a human-readable data format used for configuration files and data storage, with a clean syntax based on indentation rather than brackets or tags
• It supports common data types like strings, numbers, lists, and nested objects, making it easy to represent structured information
• **Widely used in DevOps and web development **for Docker, Kubernetes, CI/CD pipelines, and API documentation due to its simplicity and readability

Question 7

7- Which part of the Linux mail process is responsible for sending emails to remote hosts?

• MUA
• MTA
• MDA
• Evolution

Answer 7

MTA

The MTA package is responsible for connecting with remote mail hosts to deliver email messages, so option B is correct. The MUA allows clients to connect to the email server to read their messages, so option A is incorrect. The MDA allows you to create rules for processing mail locally, not to remote servers, so option C is incorrect. Evolution is an email MUA client application, not a server MTA package. The Evolution package is a graphical email client, so option D is incorrect.

Question 8

MUA

Answer 8

Mail User Agent: The email client software users interact with to read, compose, and manage emails (like Thunderbird, Mutt, or Alpine)

Question 9

MTA

Answer 9

Mail Transfer Agent: The server software that routes and transfers emails between mail servers across networks (like Postfix, Sendmail, or Exim)

Question 10

MDA

Answer 10

Mail Delivery Agent: The component that delivers incoming emails from the MTA to the user’s mailbox storage (like Procmail, Dovecot’s deliver, or Maildrop)

Question 11

Evolution

Answer 11

A specific MUA (mail user agent) - it’s GNOME’s integrated email client and personal information manager that handles email, calendar, contacts, and tasks

Question 12

8- Which part of the Linux mail process allows you to create filters to automatically redirect incoming mail messages?

• MUA
• MTA
• MDA
• Evolution

Answer 12

MDA

The MDA allows you to create filters to match email messages to redirect to other folders, so option C is correct. The MUA is the user interface and doesn’t control how incoming mail is delivered by the server, so option A is incorrect. The MTA delivers email to remote hosts and accepts mail from remote hosts, so option B is incorrect. The Evolution package is a graphical MUA package for clients and does not allow you to create filters to deliver email messages, so option D is incorrect.

Question 13

11- Which two software packages are used in Linux to maintain log files? (Choose two.)

• rsyslogd
• journald
• ntpd
• DHCPd

Answer 13

rsyslogd
journald

The rsyslogd program is used by SysV init systems to log events, and the journald program is used by Systemd systems to log events, so options A and B are the correct answers. The ntpd program provides time services and not logging services, so option C is incorrect. The DHCPd program is used for assigning IP addresses on a local network and not for logging services, so option D is incorrect.

Question 14

13- What software package allows a Linux server to print to a network printer?

• DHCPd
• BIND
• ntpd
• CUPS

Answer 14

CUPS

The CUPS application provides printer drivers and services that allow Linux systems to connect with local and remote printers, so option D is correct. The DHCPd program assigns IP addresses to devices on the local network but doesn’t connect to remote printers, so option A is incorrect. The BIND application provides hostname resolution services but can’t connect to printers, so option B is incorrect. The ntpd program allows you to synchronize the server time with a remote time clock but doesn’t connect to network printers, so option C is incorrect.

Question 15

CUPS

Answer 15

Common Unix Printing System: A modular printing system that manages print jobs and queues in Linux. It provides a web interface for administration, supports IPP (Internet Printing Protocol), and acts as a print server that can share printers across a network.

Question 16

BIND

Answer 16

Berkeley Internet Name Domain: The most widely used DNS server software on Linux systems. It translates domain names to IP addresses and vice versa, and can function as an authoritative name server for your domains or as a caching resolver for client queries.

Question 17

14- If you see the “named” program running in the background on your Linux server, what service does it provide?

• Network time
• Hostname resolution
• Dynamic IP address allocation
• Printing

Answer 17

Hostname resolution

The named program is part of the BIND application, which provides hostname resolution services, so option B is correct. The ntpd program is what provides network time, so option A is incorrect. The DHCPd program provides dynamic IP address allocation on a local network, so option C is incorrect. The CUPS application provides printing services on a Linux system, so option D is incorrect.

Question 18

15- Which authentication package used to be called by the name “Yellow Pages”?

• Samba
• Kerberos
• NIS
• BIND

Answer 18

NIS

The NIS package was formerly called Yellow Pages (YP), but the name had to be changed due to trademark issues, so option C is correct. The Samba package, which provides Windows client and server services in Linux, refers to a popular Latin dance, not the Yellow Pages, so option A is incorrect. The Kerberos package, which does provide authentication services in Linux, refers to the three‐headed hound that guards Hades, not the Yellow Pages, so option B is incorrect. The BIND application refers to binding a name to an IP address, which is a similar function to the Yellow Pages, but it wasn’t formerly called Yellow Pages, so option D is incorrect.

Question 19

NIS

Answer 19

Network Information Service (NIS)
* a directory service protocol
* allows multiple Linux/Unix systems to share common configuration data like user accounts, passwords, and host information across a network
* Centralized user management - NIS enables administrators to maintain user accounts, groups, and passwords in one central location rather than managing them separately on each individual machine
* Legacy protocol - While still functional, NIS has largely been replaced by more secure alternatives like LDAP due to its lack of encryption and security vulnerabilities in modern network environments

Question 20

17- The ________ package allows you to create a secure tunnel across a private network to access your local network remotely.

• BIND
• ntpd
• OpenSSH
• OpenSSL

Answer 20

OpenSSH

The OpenSSH package allows you to use certificates to establish a secure connection between two devices on the network, so option C is correct. The BIND package provides hostname resolution, not secure connections, so option A is incorrect. The ntpd package provides time services on the network, not secure connections, so option B is incorrect. The OpenSSL package allows you to create certificates used for encrypted communication but doesn’t perform the communication itself, so option D is incorrect.