View Full LPI 202-450  Exam Dumps and Practice Test Dumps

 

Question 241. Which BIND configuration statement controls whether recursive queries are permitted from specified clients?

1. allow-query
2. recursion-only
3. allow-recursion
4. query-source

Correct Answer: 3. allow-recursion

Explanation :-

The BIND allow-recursion statement controls which clients are permitted to perform recursive DNS queries. It is commonly configured inside an options block or an appropriate view. This is distinct from allow-query, which controls which clients can query the server generally. Restricting recursion is an important security measure because an openly recursive DNS server can be abused by unauthorized clients. Administrators should configure recursive access carefully, particularly on servers that are authoritative for public zones. Combining allow-recursion with appropriate interface and query restrictions helps limit unnecessary exposure while maintaining required DNS functionality.

Question 242. Which Apache directive specifies the network address and TCP port on which the server listens for HTTP requests?

1. Listen
2. ServerName
3. BindAddress
4. VirtualHostName

Correct Answer: 1. Listen

Explanation :-

The Apache Listen directive specifies the IP address and TCP port on which Apache accepts incoming connections. For example, Listen 80 causes Apache to listen for HTTP traffic on TCP port 80, while Listen 192.0.2.10:8080 restricts listening to a particular address and port. ServerName identifies the server’s hostname and does not determine the listening socket. The VirtualHost configuration uses address and port combinations to define virtual hosts, but Listen is the directive responsible for opening the listening endpoint.

Question 243. Which NFS configuration file defines the directories that a server exports to clients?

1. /etc/nfs.conf
2. /etc/fstab
3. /etc/exports
4. /etc/nfs/exports.conf

Correct Answer: 3. /etc/exports

Explanation :-

The /etc/exports file contains definitions of file systems that an NFS server makes available to clients. Each export can specify client hosts or networks and options such as read-only access, root squashing, and synchronization behavior. After modifying the file, administrators commonly use exportfs to update the active export table. /etc/fstab is primarily used for defining file systems to mount, while /etc/nfs.conf contains NFS service configuration rather than the primary export list. Correct export configuration is essential for controlling which clients can access shared file systems.

Question 244. Which Samba command can be used to list the shares offered by a remote SMB server?

1. smbshow
2. smbclient -L
3. smbshare -l
4. smbstatus -L

Correct Answer: 2. smbclient -L

Explanation :-

The smbclient -L command lists the shares available on a remote SMB/CIFS server. For example, smbclient -L //server.example.com can display available disk shares, printers, and other published resources, subject to authentication and server permissions. This makes the command useful when troubleshooting Samba connectivity or verifying that a server is publishing the expected shares. smbstatus instead reports information about current Samba connections and locks on a local Samba server. The smbclient utility can also be used interactively to access individual SMB shares.

Question 245. Which DNS record is normally used to identify the authoritative name servers for a DNS zone?

1. MX
2. SOA
3. CNAME
4. NS

Correct Answer: 4. NS

Explanation :-

NS records identify the authoritative name servers for a DNS zone. They are essential to DNS delegation because a parent zone uses NS records to identify the servers responsible for answering authoritatively for a delegated child zone. An SOA record provides administrative information about the zone and identifies the primary name server in its MNAME field, but it is not the record type used to list the zone’s authoritative name servers. MX records identify mail servers, while CNAME records create aliases. Administrators can inspect NS records with tools such as dig NS example.com.

Question 246. Which DHCP message does a client normally send after receiving a DHCPOFFER to request the offered configuration?

1. DHCPREQUEST
2. DHCPACK
3. DHCPDECLINE
4. DHCPINFORM

Correct Answer: 1. DHCPREQUEST

Explanation :-

A DHCP client normally sends a DHCPREQUEST after receiving one or more DHCPOFFER messages. The request indicates which offered configuration the client wants to accept. The selected DHCP server then normally responds with DHCPACK to confirm the lease. DHCPDECLINE is used when the client detects that an offered address is already in use, while DHCPINFORM allows a client that already has an address to request additional configuration information. Understanding this message sequence is important when troubleshooting address-assignment failures and identifying whether a problem occurs during discovery, offer, request, or acknowledgment.

Question 247. Which Postfix parameter identifies the network interfaces on which the SMTP service should listen?

1. mynetworks
2. inet_interfaces
3. smtp_interfaces
4. listen_interfaces

Correct Answer: 2. inet_interfaces

Explanation :-

The Postfix inet_interfaces parameter specifies the network interfaces or addresses on which Postfix accepts incoming SMTP connections. Its value can be configured to listen on all interfaces or selected addresses depending on the server’s role. This setting is different from mynetworks, which identifies trusted client networks that are allowed to relay under the configured policy. inet_protocols controls which IP protocols are used, such as IPv4 or IPv6. Incorrect inet_interfaces configuration can cause Postfix to listen only on localhost or fail to accept connections on an intended network interface.

Question 248. Which Dovecot protocol is normally used by clients to access and manage mail stored on a remote server while keeping messages on the server?

1. SMTP
2. POP3
3. IMAP
4. LMTP

Correct Answer: 3. IMAP

Explanation :-

IMAP is designed for accessing and managing mailboxes while messages remain stored on the mail server. It supports folders, message flags, synchronization, and access from multiple devices. POP3 traditionally focuses on downloading messages to a client and has fewer mailbox-management capabilities. SMTP is primarily used for mail submission and transfer between mail systems, while LMTP is commonly used for local delivery from a mail transfer agent to a mail delivery service. Dovecot commonly provides IMAP and POP3 services, making it an important component of Linux-based email infrastructure.

Question 249. Which SSH configuration directive specifies the maximum number of authentication attempts permitted per connection?

1. MaxAuthTries
2. AuthenticationLimit
3. LoginAttempts
4. MaxLoginTries

Correct Answer: 1. MaxAuthTries

Explanation :-

The OpenSSH MaxAuthTries directive specifies the maximum number of authentication attempts permitted per connection. This can help limit repeated authentication attempts during a single SSH session. It is configured in the SSH server configuration file, commonly /etc/ssh/sshd_config. Other controls such as MaxStartups govern unauthenticated concurrent connections rather than the number of authentication attempts within one connection. Administrators should distinguish these settings because they address different aspects of SSH access control. After modifying the SSH daemon configuration, the configuration should be validated before reloading the service.

Question 250. Which command displays detailed SELinux status information, including the current mode and loaded policy?

1. getenforce -v
2. selinuxctl status
3. sestatus
4. seinfo –status

Correct Answer: 3. sestatus

Explanation :-

The sestatus command provides detailed information about SELinux status. Its output can include whether SELinux is enabled, the current enforcement mode, the loaded policy, and related configuration information. By comparison, getenforce provides only the current enforcement state such as Enforcing, Permissive, or Disabled. Administrators commonly use sestatus during troubleshooting when they need more context than a simple enforcement-mode check. Understanding the difference between these commands is useful when determining whether an access problem may be related to SELinux policy enforcement.

Question 251. Which nftables object normally contains packet-filtering rules and is attached to a hook such as input or forward?

1. Set
2. Chain
3. Map
4. Counter

Correct Answer: 2. Chain

Explanation :-

An nftables chain normally contains the rules used to process packets. Base chains can be attached to hooks such as input, output, or forward, allowing the kernel to invoke those rules at appropriate points in packet processing. Tables organize chains, while sets and maps provide data structures that rules can use for matching. Counters track traffic statistics. Understanding the hierarchy of tables, chains, rules, sets, and hooks is essential when managing nftables because rules are not attached directly to tables; they are placed within chains that provide the processing context.

Question 252. Which DNS command option directs dig to query a specific DNS server?

1. -s
2. –server
3. @
4. -n

Correct Answer: 3. @

Explanation :-

In dig, the @ syntax specifies the DNS server that should receive the query. For example, dig @192.0.2.53 example.com sends the query directly to the DNS server at that address rather than relying on the system’s default resolver. This is particularly useful when testing authoritative servers, validating configuration changes, or comparing responses from different DNS servers. The query can also specify a record type, such as dig @192.0.2.53 example.com MX. This capability makes dig an important diagnostic utility for DNS administrators.

Question 253. Which Apache status code indicates that the requested resource could not be found?

1. 403
2. 500
3. 301
4. 404

Correct Answer: 4. 404

Explanation :-

HTTP status code 404 indicates that the requested resource could not be found on the server. In Apache troubleshooting, a 404 response commonly means that the requested URL does not map to an existing resource, although application routing and rewrite rules can also produce this result. Status 403 indicates that access is forbidden, 500 indicates an internal server error, and 301 represents a permanent redirect. Administrators should examine Apache access and error logs, URL rewriting rules, document roots, and application configuration when investigating unexpected 404 responses.

Question 254. Which command reloads the active NFS export configuration without requiring a full server reboot?

1. exportfs -r
2. nfsreload -a
3. mount -a
4. nfsctl –reload

Correct Answer: 1. exportfs -r

Explanation :-

The exportfs -r command re-exports the directories listed in /etc/exports, synchronizing the active NFS export table with the configuration file. This is commonly used after modifying NFS exports. It avoids the need to reboot the system and allows administrators to apply export configuration changes directly. mount -a processes local mount definitions from /etc/fstab, not NFS server exports. The exportfs utility also provides options for listing, adding, and removing exports, making it an important administration tool for NFS servers.

Question 255. Which Postfix command is commonly used to inspect the value of a configuration parameter?

1. postconf
2. postcheck
3. postshow
4. postcfg

Correct Answer: 1. postconf

Explanation :-

The postconf utility is used to display and manage Postfix configuration parameters. Running postconf without a parameter can display the configured parameters, while postconf parameter_name can show the value of a particular setting. For example, postconf myhostname displays the configured hostname value. This makes postconf useful when diagnosing mail-server configuration problems without manually searching through configuration files. Commands such as postqueue and postsuper serve different purposes, dealing primarily with the mail queue rather than the main Postfix configuration.

Question 256. Which Dovecot setting identifies the location where user mailboxes are stored?

1. mail_path
2. mail_location
3. mail_store
4. mail_directory

Correct Answer: 2. mail_location

Explanation :-

The Dovecot mail_location setting specifies the mailbox storage format and location. It can define where mail is stored and how Dovecot should interpret the mailbox structure. A properly configured mail_location is essential because Dovecot must know where to find users’ messages for IMAP or POP3 access. The exact syntax depends on the mailbox format and deployment. Administrators should ensure that the storage location matches the mail delivery configuration, because mismatches between the mail delivery system and Dovecot can result in users being unable to see newly delivered messages.

Question 257. Which Linux file controls the order and sources used by the Name Service Switch for resolving hostnames?

1. /etc/hostname
2. /etc/resolv.conf
3. /etc/nsswitch.conf
4. /etc/hosts.conf

Correct Answer: 3. /etc/nsswitch.conf

Explanation :-

The /etc/nsswitch.conf file controls the sources and lookup order used by the Name Service Switch. For hostname resolution, an entry such as hosts: files dns tells the system to consult local files such as /etc/hosts before DNS. This differs from /etc/resolv.conf, which primarily specifies DNS resolver parameters such as nameservers and search domains. Understanding the distinction is important when troubleshooting hostname resolution because a problem may result from lookup order, incorrect local entries, or incorrect DNS resolver configuration.

Question 258. Which command can display the routing table using the modern ip networking utility?

1. ip route
2. ip gateway
3. ip network
4. ip table

Correct Answer: 1. ip route

Explanation :-

The ip route command displays the kernel’s routing table. It can show directly connected networks, default routes, gateway information, metrics, and other routing attributes. Administrators use it to determine how Linux will forward traffic toward a destination. For example, ip route may show a default route through a gateway and specific routes for local networks. The ip utility replaces many older networking commands and provides a consistent interface for managing addresses, links, routes, and related networking objects.

Question 259. Which DNS record type provides reverse mapping from an IP address to a hostname?

1. A
2. CNAME
3. PTR
4. SRV

Correct Answer: 3. PTR

Explanation :-

A PTR record provides reverse DNS mapping from an IP address to a hostname. IPv4 reverse DNS records are stored under the in-addr.arpa domain, while IPv6 reverse DNS uses ip6.arpa. PTR records are commonly used by network services, logging systems, and mail servers when checking reverse name resolution. An A record maps a hostname to an IPv4 address, CNAME creates a hostname alias, and SRV identifies services and their associated hosts and ports. Correct reverse DNS configuration is particularly important for services that perform hostname or reputation checks based on client IP addresses.

Question 260. Which command can test whether an SSH server is reachable on a specific TCP port without establishing an SSH login session?

1. ssh-keyscan
2. ssh -p
3. nc -z
4. sshd-test

Correct Answer: 3. nc -z

Explanation :-

The nc -z option allows netcat to scan or test whether a TCP port is accepting connections without transmitting application data. For example, nc -zv server.example.com 22 can test whether TCP port 22 is reachable and listening. This can help distinguish basic network or firewall problems from SSH authentication and configuration problems. ssh -p specifies the port for an actual SSH connection, while ssh-keyscan retrieves SSH host keys. Administrators can therefore use nc as a simple network-level diagnostic before investigating higher-level SSH authentication issues.