202-450 LPIC-2 - Exam 202 (part 2 of 2), version 4.5 Free Practice Exam Questions (2025 Updated)

Sieve filters are usually applied to an email when the email is delivered to a mailbox by a mail delivery agent (MDA) or a local delivery agent (LDA). Sieve filters are scripts that can perform various actions on incoming emails, such as sorting them into folders, assigning labels, forwarding, rejecting, or discarding them. Sieve filters are executed on the server side, and they are independent of the mail user agent (MUA) or the mail access protocol. This means that the email filtering is consistent across different email clients and devices. Sieve filters are not applied when the email is relayed by an SMTP server, received by an SMTP smarthost, sent to the first server by an MUA, or retrieved by an MUA. These are different stages of the email delivery process, but they do not involve the final delivery of the email to a mailbox.

References:

LPIC-2 Exam 202 Objectives, Objective 205.4: Managing a dovecot server

Sieve filter (advanced custom filters) | Proton

start - Sieve.Info

What is Sieve Filtering? - Knowledge Base - Pair Networks

 The Apache HTTPD configuration directive that specifies the RSA private key that was used in the generation of the SSL certificate for the server is SSLCertificateKeyFile1. This directive sets the file path and name of the file containing the server private key2. The private key is used to decrypt the data that is encrypted with the public key contained in the certificate1. The private key must match the certificate, otherwise an error will occur when starting the server2. The other options are not valid directives for Apache HTTPD. References:

mod_ssl - Apache HTTP Server Version 2.4

Why is SSLCertificateKeyFile needed for Apache? - Stack Overflow

The root element of the LDAP tree holding the configuration of an OpenLDAP server that is using directory based configuration is called cn=config. This is a special entry that is not part of the regular data DITs, but rather a separate DIT that can be used to configure the OpenLDAP server online. The cn=config entry contains various subentries that define the global and database-specific settings for the server. The cn=config entry can be accessed and modified using standard LDAP tools and methods, such as ldapsearch and ldapmodify12.

References:

OpenLDAP Software 2.6 Administrator’s Guide: Configuring slapd: The official documentation of OpenLDAP on how to configure the slapd daemon, which includes the description of the cn=config entry and its subentries.

How To Configure OpenLDAP and Perform Administrative LDAP Tasks | DigitalOcean: A tutorial from DigitalOcean on how to configure OpenLDAP and perform administrative LDAP tasks, which includes the use of the cn=config entry and the ldapsearch and ldapmodify tools.

The Samba service that handles the membership of a file server in an Active Directory domain is winbindd. Winbindd is a daemon that provides a number of services to the Name Service Switch (NSS) capability of the system, such as resolving user and group information from a Windows NT server and authentication. Winbindd can also be used to join a Samba file server to an Active Directory domain and authenticate domain users to access the file shares12 References:

Chapter 4. Using Samba for Active Directory Integration Red Hat Enterprise Linux 7 - Red Hat Customer Portal

Winbind: Use of Domain Accounts - SambaWiki

 In the context of configuring Nginx for reverse proxy, the proxy_pass directive is used to specify the protocol and address of a proxied server and an optional URI to which a location should be mapped. So, in the provided configuration sample, “proxy_pass” is the missing keyword that should precede “http://proxiedserver:8080;”.

References:

[NGINX Docs | NGINX Reverse Proxy]: The official documentation of Nginx on how to set up a reverse proxy with Nginx.

[How To Configure Nginx as a Web Server and Reverse Proxy for Apache on One Ubuntu 20.04 Server | DigitalOcean]: A tutorial from DigitalOcean on how to configure Nginx as a web server and reverse proxy for Apache on Ubuntu 20.04, which includes the use of the proxy_pass directive.

 The line A is valid in a configuration file in /etc/pam.d/ because it follows the correct syntax and semantics of a PAM configuration file. The syntax of a PAM configuration file is:

module_interface control_flag module_name module_arguments

The module_interface specifies the type of authentication action that the module can perform. There are four types of module interface: auth, account, password, and session. The control_flag specifies how important the success or failure of the module is to the overall authentication process. There are four types of control flag: required, requisite, sufficient, and optional. The module_name specifies the name of the library that contains the module. The module_arguments are optional parameters that can modify the behavior of the module.

The line A has the following components:

module_interface: auth, which means the module is used for user authentication.

control_flag: required, which means the module must succeed for authentication to continue. If the module fails, the failure is recorded and the rest of the modules are executed.

module_name: pam_unix.so, which means the module is the standard Unix authentication module that verifies the user’s password against the /etc/passwd and /etc/shadow files.

module_arguments: try_first_pass nullok, which means the module tries to use the password that was previously entered by the user (if any), and allows users with empty passwords to log in.

The line B is invalid because it has the wrong order of the fields. The control_flag should come before the module_name, not after. The line C is invalid because it uses parentheses and colons instead of spaces to separate the fields. The line D is invalid because it has the wrong syntax for the control_flag. The control_flag should be a single word, not a word in parentheses.

 The keyword that is used in the Squid configuration to define networks and times used to limit access to the service is acl. The acl keyword stands for access control list, and it is used to create rules that match certain criteria, such as source or destination IP address, port number, URL, protocol, time, or user name. The acl keyword is followed by a name and a type, and optionally some arguments or a file name. For example, the following lines define two acl rules named localnet and daytime:

acl localnet src 192.168.0.0/16 # match local network acl daytime time 08:00-18:00 # match working hours

The acl rules can then be used with other keywords, such as http_access, to allow or deny access to the Squid service based on the matching criteria. For example, the following line allows access to the Squid service only from the local network and only during working hours:

http_access allow localnet daytime

The acl keyword is one of the most important and versatile keywords in the Squid configuration, and it can be used to create complex and flexible access policies. For more information about the acl keyword and its types and arguments, you can refer to the following resources:

1: A Squid documentation page that explains the syntax and usage of the acl keyword and its types and arguments.

2: A Squid documentation page that provides examples of common acl rules and how to use them.

3: A Squid FAQ page that answers some frequently asked questions about acl rules and how they work.

 The host allow option in the smb.conf file specifies the hosts or networks that are allowed to access the Samba server. The hosts can be specified by name, IP address, or network address with a netmask. The host allow option can also include the special name localhost, which refers to the local machine. The host allow option can be overridden by the host deny option, which specifies the hosts or networks that are denied access to the Samba server. The host deny option has a higher priority than the host allow option.

In this question, the host allow option is set to 192.168.1.100 192.168.2.0/24 localhost, which means that only the host with the IP address 192.168.1.100, the hosts on the network 192.168.2.0/24 (from 192.168.2.1 to 192.168.2.254), and the local machine can access the Samba server. This explains why a wireless laptop with an IP address 192.168.2.93 can access the Samba server, but a workstation on the wired network with an IP address 192.168.1.177 cannot. Almost every machine on the wired network is unable to access the Samba server because they are not included in the host allow option.

To fix this problem, the host allow option should be changed to include the entire wired network, which is assumed to be 192.168.1.0/24 (from 192.168.1.1 to 192.168.1.254). This can be done by using the network address and the netmask, or by using a range of IP addresses. The host allow option should also keep the wireless network and the localhost in the list, so that the existing access is not denied. Therefore, the correct answer is E. host allow = 192.168.1.0/255.255.255.0 192.168.2.0/255.255.255.0 localhost. This will allow any host on either network, or the local machine, to access the Samba server, without denying access to anyone else.

 The ErrorLog directive of the Apache HTTPD server defines the location and name of the file where the server will log any errors it encounters. The default value of this directive is logs/error_log, which means that the error log file will be stored in the logs subdirectory of the server root directory. The ErrorLog directive can also accept a filename relative to the server root, an absolute filename, or a pipe to a program that will handle the logging. For example, ErrorLog logs/my_error_log will store the error log file in the logs subdirectory with the name my_error_log, ErrorLog /var/log/httpd/error_log will store the error log file in the /var/log/httpd directory with the name error_log, and ErrorLog “|bin/rotatelogs logs/error_log 86400” will pipe the error log to the rotatelogs program that will rotate the log file every 86400 seconds. References: Log Files - Apache HTTP Server Version 2.4, Directive Quick Reference - Apache HTTP Server Version 2.4, How do I find Apache http server log files? – Code A Site Blog, mod_log_config - Apache HTTP Server Version 2.2

 The error message in the image is saying that the program vsftpd is unable to find the required shared library file. This is because the program is running in a chroot jail, which restricts the program’s access to the file system. To fix this error, the required library file must be copied to the appropriate lib directory in the chroot jail. This will allow the program to access the file and run properly. References:

LPIC-2 Overview

LPIC-2 201-450

LPIC-2 202-450

To create a hidden Samba share, similar to the Windows Administration Share, the share name must end with a dollar sign ().Thiswillpreventthesharefrombeinglistedinthebrowselist,butitcanstillbeaccessedbytypingthefullsharename.OptionAshowsanexampleofahiddenSambasharenamedconfidential, with some additional parameters to configure the share. Option B is incorrect because the share name does not end with a dollar sign. Option C is incorrect because the share name is not enclosed in brackets. Option D is incorrect because the share name contains a space, which is not allowed. Option E is incorrect because the share name is not a valid file name12 References:

Hiding samba share from browse list for unauthorised users

Creating a samba share where everyone has write access

The tool dig, which stands for domain information groper, is a command-line utility that provides the most information when performing DNS queries, without any options. Dig can query any type of DNS record and display the full response from the DNS server, including the header, question, answer, authority, and additional sections. Dig can also show the query time, server address, response code, flags, and statistics. Dig is a versatile and powerful tool that can be used for troubleshooting, testing, and debugging DNS issues123 References:

dig(1) - Linux manual page

How to Use the Dig Command on Linux

How to use the dig command for DNS queries on Linux

 DHCPv6 supports three types of IPv6 address assignments:

Individual address assignment (IA_NA): This is the stateful mode of DHCPv6, where the DHCPv6 server assigns a normal IPv6 address to a client that can be renewed or released. The address is chosen from a pool of prefixes configured on the server and is unique and non-duplicate. The client can request one or more addresses using the IA_NA option in the DHCPv6 messages1

Temporary address assignment (IA_TA): This is similar to the IA_NA mode, but the addresses assigned are temporary and cannot be renewed or released. The temporary addresses are used for privacy reasons and are generated by the client using a random interface identifier. The client can request one or more temporary addresses using the IA_TA option in the DHCPv6 messages2

Prefix delegation (IA_PD): This is the mode where the DHCPv6 server delegates a whole IPv6 prefix to a client, such as a router or a host, that can use it for further subnetting or routing. The client can request one or more prefixes using the IA_PD option in the DHCPv6 messages. The delegated prefixes are also chosen from a pool of prefixes configured on the server3

References: 1: IP Addressing: DHCP Configuration Guide - IPv6 Access Services: DHCPv6 Individual Address Assignment 2: RFC 4941 - Privacy Extensions for Stateless Address Autoconfiguration in IPv6 3: IP Addressing: DHCP Configuration Guide - IPv6 Access Services: DHCPv6 Prefix Delegation

The ldappasswd command is used to change user passwords in an OpenLDAP directory. It allows users to change their own passwords or administrators to change other users’ passwords. It requires the user to bind to the LDAP server with the current password and then specify the new password using various options. The ldappasswd command follows the same general syntax as the other OpenLDAP tools and supports various options to modify the password operation. The ldappasswd command is part of the OpenLDAP software package and is compliant with the LDAP Password Modify Extended Operation defined in RFC 3062. References:

How To Change Account Passwords on an OpenLDAP Server

OpenLDAP ACL to allow users to change their password

[ldappasswd(1) - Linux man page]

[RFC 3062 - LDAP Password Modify Extended Operation]

 TSIG stands for Transaction SIGnature, which is a mechanism for authenticating DNS messages using a shared secret key and a cryptographic hash algorithm. TSIG can be used to secure DNS updates, zone transfers, and queries between DNS servers and clients. To configure a BIND server to use TSIG, the following parameters should be added to the named.conf file:

A key statement that defines the name, algorithm, and secret of the TSIG key. The name can be any arbitrary string, the algorithm can be one of the supported algorithms such as hmac-md5, hmac-sha1, hmac-sha256, etc., and the secret can be a base64-encoded string that represents the shared secret key. For example:

key “server.example.com” { algorithm hmac-md5; secret “skrKc4DoTzi/takIlPi7JZA==”; };

A server statement that specifies the IP address or hostname of the remote server that will use the TSIG key, and the name of the key that should be used for communication. For example:

server 192.168.1.10 { keys { “server.example.com”; }; };

A zone statement that indicates the zone name, type, and file of the zone that will use TSIG, and the name of the key that should be used for updates or transfers. For example:

zone “example.com” { type master; file “example.com.zone”; allow-update { key “server.example.com”; }; allow-transfer { key “server.example.com”; }; };

Option E shows the correct configuration parameters that should be added if the server should use the algorithm hmac-md5 and the key skrKc4DoTzi/takIlPi7JZA==. The other options are incorrect because they either use the wrong syntax, the wrong algorithm, the wrong key name, or the wrong secret.

References:

LPIC-2 exam 202 objectives, topic 208.2, “Securing a DNS server”

BIND 9 Administrator Reference Manual, chapter 6, “Access Control Lists and TSIG”

How to Configure DNS Server with TSIG on CentOS 8

Server Name Indication (SNI) is an extension to the Transport Layer Security (TLS) protocol that allows a client to indicate which hostname it is trying to connect to at the start of the handshaking process1. This enables the server to present the appropriate certificate for the requested hostname, and thus allows multiple SSL/TLS secured virtual HTTP hosts to coexist on the same IP address12. SNI does not support transparent failover of TLS sessions from one web server to another, as this would require session resumption or renegotiation mechanisms1. SNI does not enable HTTP servers to update the DNS of their virtual hosts’ names using the X 509 certificates of the virtual hosts, as this would require a different protocol such as Dynamic DNS1. SNI does not provide a list of available virtual hosts to the client during the TLS handshake, as this would expose the server’s configuration and potentially compromise its security1. SNI submits the host name of the requested URL during the TLS handshake, as this is the information that the client needs to communicate to the server in order to select the correct certificate12. References:

Server Name Indication - IBM

Server Name Indication - Wikipedia

The Samba configuration parameter writeable is a synonym for the parameter read only. It has the opposite meaning, so setting writeable=no is equivalent to setting read only=yes. This parameter controls whether a user has the ability to create or modify files within a share12 References:

LPIC-2 Overview

LPIC-2 202-450

smb.conf - Samba

Samba share permissions simplified - nixCraft

 The options rw and ro are valid in /etc/exports. They specify whether the exported file system is mounted with read-write or read-only permissions by the clients. The option rw allows the clients to modify the files on the server, while the option ro prevents any changes by the clients. These options can be applied to all or specific hosts in the /etc/exports file123 References:

LPIC-2 Overview

LPIC-2 202-450

10 practical examples to export NFS shares in Linux | GoLinuxCloud

 The sender_canonical_maps parameter on a Postfix server specifies an optional address mapping that applies when mail is delivered (sent) from the server. This mapping can be used to rewrite the sender address of outgoing messages to a different format or domain. For example, the following sender_canonical_maps entry will rewrite the sender address from user@localdomain to user@example.com:

user@localdomain user@example.com

The sender_canonical_maps parameter only affects the sender address and not the recipient address. The recipient address can be modified by other parameters such as recipient_canonical_maps or virtual_alias_maps.

References: You can learn more about sender_canonical_maps and other Postfix address rewriting parameters from the following sources:

Postfix Address Rewriting

Postfix Configuration Parameters

Postfix Generic Mapping for Outgoing SMTP Mail