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

 

Question 321. Which BIND directive specifies the IP addresses and ports on which named accepts DNS queries?

1. allow-query
2. query-source
3. listen-on
4. query-address

Correct Answer: 3. listen-on

Explanation :-

The BIND listen-on directive specifies the IPv4 addresses and ports on which the DNS server listens for incoming queries. It determines where the named process accepts DNS traffic, while allow-query controls which clients are permitted to submit queries. These settings therefore address different aspects of DNS access. For IPv6, BIND provides the corresponding listen-on-v6 statement. Proper interface configuration is useful on multi-homed systems where DNS service should be available only through selected network interfaces. Administrators should verify both listening addresses and client permissions when troubleshooting DNS connectivity.

Question 322. Which Apache directive specifies the directory containing the files served by a virtual host?

1. DocumentRoot
2. WebRoot
3. SiteDirectory
4. ServerRoot

Correct Answer: 1. DocumentRoot

Explanation :-

The Apache DocumentRoot directive specifies the directory from which Apache serves files for a website or virtual host. For example, DocumentRoot /var/www/example tells Apache where to look for requested web resources. ServerRoot instead identifies the base directory containing server configuration and related files. A correct DocumentRoot is essential for serving the intended content. When troubleshooting unexpected 404 responses, administrators should check the requested URL, the configured DocumentRoot, file existence, permissions, and any rewrite or alias rules that may affect how Apache maps URLs to files.

Question 323. Which NFS option makes an exported file system available only for read operations?

1. readonly
2. ro
3. no_write
4. read_only

Correct Answer: 2. ro

Explanation :-

The NFS ro export option makes an exported file system read-only for clients. Clients can retrieve files but cannot normally perform write operations through the NFS mount. This can be useful for shared software, reference data, documentation, or other content that should not be modified by clients. The server-side export configuration can also use rw when write access is intended. Administrators should remember that NFS export permissions and local Unix permissions both influence access. A client-side mount option alone does not necessarily provide the same administrative control as enforcing the intended access mode on the server.

Question 324. Which Samba command displays information about current connections and file locks?

1. smbclient -L
2. smbstatus
3. testparm -s
4. smbinfo

Correct Answer: 2. smbstatus

Explanation :-

The smbstatus utility displays information about active Samba connections, locked files, and sessions associated with the Samba server. It is useful when investigating which users are connected to shares or why a file may be reported as busy. smbclient -L is used to discover shares on an SMB server, while testparm checks Samba configuration. Administrators can use smbstatus during operational troubleshooting to identify active sessions and resources. The exact information displayed depends on the Samba version and the privileges of the user running the command.

Question 325. Which DNS record specifies the preferred mail servers for a domain?

1. MX
2. MAIL
3. SMTP
4. MTA

Correct Answer: 1. MX

Explanation :-

An MX record identifies the mail exchangers responsible for receiving email for a domain. Each MX record can contain a preference value, allowing multiple mail servers to be arranged according to priority. Sending mail systems query the recipient domain’s MX records to determine where messages should be delivered. The hostname named by an MX record must resolve through address records such as A or AAAA. MX is a DNS record type; SMTP is the protocol used for transferring mail between systems. Administrators can inspect MX records with dig MX domain.example.

Question 326. Which DHCP option provides clients with the addresses of DNS servers?

1. Option 3
2. Option 6
3. Option 12
4. Option 15

Correct Answer: 2. Option 6

Explanation :-

DHCP option 6 supplies clients with DNS server addresses. A DHCP server can use this option to tell clients which recursive resolvers they should use for hostname resolution. Option 3 specifies routers or default gateways, option 12 provides the client hostname, and option 15 specifies the domain name. Correct DNS-server information is important because a client may have valid IP connectivity while still being unable to resolve hostnames if its resolver configuration is missing or incorrect. Administrators can inspect the resulting configuration using platform-specific network-management tools.

Question 327. Which Postfix parameter identifies domains for which the server should perform local delivery?

1. mydestination
2. local_domains
3. mydomains
4. local_destinations

Correct Answer: 1. mydestination

Explanation :-

The Postfix mydestination parameter specifies the domains and hostnames for which Postfix considers itself the final delivery destination. Mail addressed to these destinations is handled as local mail rather than being relayed to another server. This parameter is distinct from relay_domains, which identifies destinations for which Postfix provides relay service. mynetworks identifies trusted networks, while myorigin influences the domain used for locally submitted mail. Correct configuration is important because an incorrect mydestination value can cause local messages to be rejected, misrouted, or handled as relay traffic.

Question 328. Which Dovecot setting defines the authentication database used to determine a user’s mailbox location and account information?

1. passdb
2. maildb
3. userdb
4. authdb

Correct Answer: 3. userdb

Explanation :-

Dovecot’s userdb configuration provides user-specific information needed after authentication, such as mailbox location, UID, GID, and related account attributes. The passdb configuration instead provides the authentication credentials or password-verification source. Keeping these functions separate allows Dovecot to authenticate users against one source while obtaining mailbox information from another. This distinction is useful when troubleshooting login problems. If authentication succeeds but the user’s mailbox cannot be found or opened correctly, administrators should investigate userdb configuration and the returned user attributes.

Question 329. Which SSH option requests allocation of a pseudo-terminal for the remote session?

1. -x
2. -t
3. -T
4. -n

Correct Answer: 2. -t

Explanation :-

The SSH client -t option requests allocation of a pseudo-terminal on the remote system. This is useful when executing commands remotely that expect an interactive terminal, such as commands requiring terminal-based input or output. SSH can sometimes allocate a terminal automatically for interactive sessions, but explicit -t is useful in scripts or specific remote command scenarios. The -T option disables pseudo-terminal allocation. Other SSH options control X11 forwarding, standard input handling, identity files, and ports. Understanding terminal allocation is useful when troubleshooting commands that behave differently during non-interactive SSH execution.

Question 330. Which SELinux utility can be used to change a file’s security context manually?

1. chcon
2. setcontext
3. selabel
4. chmodcon

Correct Answer: 1. chcon

Explanation :-

The chcon command changes the SELinux security context of a file or directory manually. It can be useful for testing or temporary context adjustments, but manually assigned contexts may not persist as expected after a full context restoration. For persistent policy-based labeling, administrators generally use file-context definitions and then apply them with restorecon. This distinction is important because changing a context with chcon does not necessarily update the system’s default labeling rules. When troubleshooting SELinux, administrators should identify the expected context and determine whether the file is correctly labeled according to policy.

Question 331. Which nftables command displays all currently configured tables, chains, and rules?

1. nft show firewall
2. nft display all
3. nft list ruleset
4. nft status

Correct Answer: 3. nft list ruleset

Explanation :-

The nft list ruleset command displays the active nftables ruleset, including configured tables, chains, and rules. It is commonly used when auditing firewall configuration or troubleshooting unexpected packet behavior. Administrators can use more specific commands, such as nft list table inet filter, when they need to inspect only one table. The complete ruleset is useful for understanding rule order and identifying policies that may be affecting traffic. Because nftables configuration can contain multiple address families and tables, reviewing the entire ruleset can reveal interactions that are not obvious when inspecting a single chain.

Question 332. Which DNS record type is used for reverse resolution of an IPv4 address?

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

Correct Answer: 2. PTR

Explanation :-

A PTR record provides reverse DNS mapping from an IP address to a hostname. For IPv4, reverse DNS records are stored beneath the in-addr.arpa namespace. For example, an IPv4 address is represented by reversing its octets within that namespace before the PTR record is queried. A records perform the opposite type of mapping from hostname to IPv4 address. CNAME records create aliases between names. Reverse DNS is used by many network services for identification, logging, and validation, so incorrect PTR configuration can lead to unexpected results during service troubleshooting.

Question 333. Which Apache directive specifies a custom response document for a particular HTTP error code?

1. ErrorDocument
2. ErrorPage
3. HTTPError
4. CustomError

Correct Answer: 1. ErrorDocument

Explanation :-

The Apache ErrorDocument directive specifies what Apache should return when a particular HTTP error occurs. For example, ErrorDocument 404 /404.html tells Apache to serve a custom resource when a requested resource is not found. It can also be configured for other status codes such as 403 and 500. Custom error documents can improve user experience while still providing useful information. Administrators should ensure that the configured error resource itself is accessible and does not trigger additional errors, which could complicate troubleshooting or create unexpected response behavior.

Question 334. Which NFS utility can display currently mounted NFS file systems and related mount information?

1. nfsstat
2. showmount
3. mount
4. exportfs

Correct Answer: 3. mount

Explanation :-

The mount command, when used without arguments, can display currently mounted file systems, including NFS mounts on many Linux systems. Administrators can inspect the output to verify whether an NFS share is mounted and determine the associated mount point and options. showmount queries an NFS server’s exported resources, while exportfs manages server-side exports. nfsstat provides protocol statistics. When troubleshooting an NFS client, verifying that the expected share is actually mounted is an important step before investigating file permissions or application-level problems.

Question 335. Which Postfix utility displays the contents of the mail queue?

1. postqueue
2. postmail
3. postshow
4. poststatus

Correct Answer: 4. postqueue

Explanation :-

The postqueue utility is used to inspect and manage the Postfix mail queue. The postqueue -p form displays queued messages and information such as queue IDs, senders, recipients, sizes, and delivery status. The utility can also request queue processing with appropriate options. postsuper performs administrative operations on queued messages, such as deleting or holding them. Reviewing the queue is a common troubleshooting step when mail is delayed because it helps determine whether messages are waiting for delivery and provides clues about the destination or reason for the delay.

Question 336. Which Linux file defines the system’s configured DNS resolver addresses on many traditional Linux installations?

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

Correct Answer: 3. /etc/resolv.conf

Explanation :-

The /etc/resolv.conf file traditionally contains DNS resolver configuration, including nameserver entries and optional search domains. For example, a nameserver 192.0.2.53 line identifies a DNS resolver that applications can use. Modern Linux systems may generate this file dynamically through NetworkManager, systemd-resolved, or another network-management service, so administrators should check how the particular system manages resolver configuration. /etc/nsswitch.conf controls the order of name-service sources, while /etc/hosts contains local static hostname mappings.

Question 337. Which SSH configuration directive specifies the TCP port on which the SSH daemon listens?

1. SSHPort
2. ListenPort
3. Port
4. DaemonPort

Correct Answer: 3. Port

Explanation :-

The OpenSSH server Port directive specifies the TCP port on which sshd listens for incoming connections. The default SSH port is 22, but administrators may configure another port when required. The setting is normally placed in /etc/ssh/sshd_config. Changing the SSH port does not itself provide comprehensive security because other authentication and network controls remain important. When changing the port remotely, administrators should ensure that firewall rules, client commands, and service configuration are updated consistently to avoid losing administrative access.

Question 338. Which SELinux command can restore expected security contexts recursively under a directory?

1. restorecon -R
2. setcon -R
3. chcon –default
4. selinuxfix -r

Correct Answer: 1. restorecon -R

Explanation :-

The restorecon -R command recursively restores SELinux file contexts beneath a specified directory according to the system’s file-context policy. For example, administrators may use restorecon -Rv /var/www/html after copying web content into a location with incorrect labels. The recursive option ensures that files and subdirectories are processed. This is preferable to manually assigning contexts to individual files when the expected labels are already defined by SELinux policy. Administrators should use the appropriate path carefully because recursive context restoration can affect many files.

Question 339. Which DNS utility can trace the delegation path from the root DNS servers to an authoritative server?

1. dig +trace
2. host –delegate
3. named –trace
4. dnsroute

Correct Answer: 1. dig +trace

Explanation :-

The dig +trace option performs an iterative DNS resolution process starting from the root servers and following referrals toward the requested domain. It is useful for investigating delegation, authoritative-server selection, and DNS resolution problems. Rather than relying entirely on a recursive resolver’s cached response, the trace reveals the sequence of DNS servers involved in reaching the authoritative zone. Administrators can use this when diagnosing broken delegations, missing NS records, or incorrect authoritative responses. Network connectivity and access to DNS servers must still be available for the trace to work properly.

Question 340. Which Linux command displays detailed information about a network interface, including its link state and MAC address?

1. ip route show
2. ip addr show
3. ip link show
4. ip net show

Correct Answer: 3. ip link show

Explanation :-

The ip link show command displays link-layer information for network interfaces, including interface state, MAC address, MTU, and other link attributes. It is useful for determining whether an interface is administratively or operationally up and for identifying its hardware address. ip addr show focuses more on assigned IP addresses and address-related configuration, while ip route show displays routing information. During network troubleshooting, administrators commonly inspect both link information and IP addressing because an interface can be present and configured while still being down or disconnected.