DNS (Domain Name System) MCQs
What is the primary function of DNS in computer networks?
a) Encrypting data transmissions
b) Resolving domain names to IP addresses
c) Filtering network traffic
d) Managing network security policies
Answer: b) Resolving domain names to IP addresses
Which DNS record type is used to map a domain name to an IPv4 address?
a) MX
b) AAAA
c) CNAME
d) A
Answer: d) A
What is the maximum length of a fully qualified domain name (FQDN) in DNS?
a) 64 characters
b) 128 characters
c) 256 characters
d) 512 characters
Answer: c) 256 characters
Which DNS record type is used to specify mail servers responsible for accepting email on behalf of a domain?
a) A
b) MX
c) PTR
d) CNAME
Answer: b) MX
What does a PTR record in DNS primarily do?
a) Maps an IP address to a domain name
b) Provides authoritative name servers for a domain
c) Resolves a domain name to an IPv6 address
d) Maps an IP address to a domain for reverse DNS lookup
Answer: d) Maps an IP address to a domain for reverse DNS lookup
Which DNS record type is used to alias one domain name to another?
a) PTR
b) A
c) MX
d) CNAME
Answer: d) CNAME
What is the purpose of a TTL (Time-to-Live) value in DNS records?
a) Ensures secure DNS transactions
b) Specifies the maximum file size for DNS zone files
c) Determines how long DNS information can be cached by resolvers
d) Encrypts DNS queries and responses
Answer: c) Determines how long DNS information can be cached by resolvers
Which DNS record type is used to associate an IPv6 address with a domain name?
a) AAAA
b) A
c) CNAME
d) MX
Answer: a) AAAA
What is the purpose of a DNS zone transfer?
a) Authenticates DNS requests between servers
b) Synchronizes DNS data across authoritative name servers
c) Encrypts DNS traffic over the internet
d) Filters malicious DNS queries
Answer: b) Synchronizes DNS data across authoritative name servers
Which DNS record type is used to delegate a subdomain to a different set of name servers?
a) NS
b) SOA
c) AAAA
d) MX
Answer: a) NS
What does the ‘SOA’ record stand for in DNS?
a) Start of Authentication
b) Source of Authority
c) Server of Access
d) System of Administration
Answer: b) Source of Authority
Which DNS record type is used to provide information about the authoritative name servers for a domain?
a) NS
b) SOA
c) AAAA
d) MX
Answer: a) NS
What is the primary role of a DNS resolver in the DNS lookup process?
a) Maintains DNS zone files
b) Queries authoritative name servers to resolve domain names
c) Updates DNS records dynamically
d) Encrypts DNS queries
Answer: b) Queries authoritative name servers to resolve domain names
Which DNS record type is used for mapping domain names to human-readable names, often used for services like FTP or WWW?
a) PTR
b) A
c) SRV
d) CNAME
Answer: d) CNAME
What is the purpose of a glue record in DNS?
a) Encrypts DNS responses for security
b) Resolves DNS queries for subdomains
c) Prevents DNS cache poisoning attacks
d) Provides IP addresses of authoritative name servers for a domain
Answer: d) Provides IP addresses of authoritative name servers for a domain
Which DNS record type is used for service discovery and identifying servers providing specific services within a domain?
a) A
b) SRV
c) CNAME
d) AAAA
Answer: b) SRV
What does DNSSEC (Domain Name System Security Extensions) primarily aim to enhance?
a) Encryption of DNS traffic
b) Authentication and integrity of DNS data
c) Filtering of malicious DNS queries
d) Dynamic updating of DNS records
Answer: b) Authentication and integrity of DNS data
Which DNS record type is used to verify the authenticity of DNS data through cryptographic signatures?
a) DNSKEY
b) DS
c) RRSIG
d) NSEC
Answer: c) RRSIG
What is the purpose of EDNS (Extension Mechanisms for DNS)?
a) Enhancing DNS query efficiency
b) Encrypting DNS queries and responses
c) Filtering malicious DNS queries
d) Resolving DNS queries for subdomains
Answer: a) Enhancing DNS query efficiency
Which DNS record type is used to provide information about the DNSKEYs that can be used to validate DNSSEC signatures?
a) DS
b) RRSIG
c) DNSKEY
d) NSEC
Answer: c) DNSKEY
What is the role of a recursive DNS resolver in DNS resolution?
a) Maintains authoritative name servers
b) Queries root DNS servers directly
c) Caches DNS responses for future use
d) Encrypts DNS queries for security
Answer: c) Caches DNS responses for future use
Which DNS record type is used to identify the responsible person for a domain name, including contact information?
a) NS
b) SOA
c) TXT
d) RP
Answer: d) RP
What is the primary role of a root DNS server in the DNS hierarchy?
a) Resolves top-level domain (TLD) queries
b) Authenticates DNS queries for security
c) Manages DNS zone transfers
d) Encrypts DNS responses
Answer: a) Resolves top-level domain (TLD) queries
Which DNS record type is used for storing arbitrary text information associated with a domain name?
a) NS
b) SOA
c) TXT
d) RP
Answer: c) TXT
What is the purpose of the root hints file in DNS configuration?
a) Encrypts DNS traffic for security
b) Provides IP addresses of root DNS servers
c) Filters DNS queries based on content
d) Resolves DNS queries for subdomains
Answer: b) Provides IP addresses of root DNS servers
Which DNS record type is used to map an IPv4 address to a domain name for reverse DNS lookup?
a) A
b) AAAA
c) PTR
d) CNAME
Answer: c) PTR
What is the purpose of DNS caching?
a) Encrypts DNS responses for security
b) Reduces DNS query response time by storing previous query results
c) Prevents DNS cache poisoning attacks
d) Updates DNS records dynamically
Answer: b) Reduces DNS query response time by storing previous query results
Which DNS record type is used for resolving domain names to IPv6 addresses?
a) A
b) AAAA
c) CNAME
d) PTR
Answer: b) AAAA
What does the ‘NS’ record stand for in DNS?
a) Network Service
b) Name Server
c) Node Security
d) Network Source
Answer: b) Name Server
Which DNS record type is used to provide additional information or comments in a DNS zone file?
a) A
b) SOA
c) PTR
d) ; (semicolon)
Answer: d) ; (semicolon)
What is the role of a stub resolver in DNS resolution?
a) Queries authoritative name servers directly
b) Provides recursive resolution for DNS queries
c) Maintains DNS zone files
d) Filters DNS queries based on content
Answer: a) Queries authoritative name servers directly
Which DNS record type is used for specifying the mail exchanger for a domain name?
a) A
b) MX
c) CNAME
d) PTR
Answer: b) MX
What does a ‘zone transfer’ refer to in DNS?
a) Dynamic updating of DNS records
b) Synchronization of DNS data between DNS servers
c) Encrypting DNS traffic for security
d) Filtering malicious DNS queries
Answer: b) Synchronization of DNS data between DNS servers
Which DNS record type is used to provide information about the responsible party for a domain name?
a) NS
b) SOA
c) RP
d) TXT
Answer: c) RP
What is the primary role of the resolver in the DNS lookup process?
a) Queries root DNS servers directly
b) Caches DNS responses for future use
c) Maintains authoritative name servers
d) Encrypts DNS queries for security
Answer: b) Caches DNS responses for future use
Which DNS record type is used to map a domain name to a human-readable name for services like FTP or WWW?
a) A
b) CNAME
c) MX
d) PTR
Answer: b) CNAME
What is the primary purpose of a resolver in the DNS resolution process?
a) Authenticates DNS queries
b) Queries authoritative name servers to resolve domain names
c) Filters malicious DNS traffic
d) Encrypts DNS responses
Answer: b) Queries authoritative name servers to resolve domain names
Which DNS record type is used for identifying servers providing specific services within a domain?
a) A
b) SRV
c) CNAME
d) AAAA
Answer: b) SRV
What does the ‘SOA’ record in DNS signify?
a) Start of Access
b) Source of Authority
c) System of Administration
d) State of Authentication
Answer: b) Source of Authority
Which DNS record type is used for verifying the authenticity of DNS data through cryptographic keys?
a) DNSKEY
b) DS
c) RRSIG
d) NSEC
Answer: c) RRSIG
What is the purpose of EDNS (Extension Mechanisms for DNS)?
a) Enhancing DNS query efficiency
b) Encrypting DNS queries and responses
c) Filtering malicious DNS queries
d) Resolving DNS queries for subdomains
Answer: a) Enhancing DNS query efficiency
Which DNS record type is used for providing information about the DNSKEYs that can be used to validate DNSSEC signatures?
a) DS
b) RRSIG
c) DNSKEY
d) NSEC
Answer: c) DNSKEY
What is the role of a recursive DNS resolver in DNS resolution?
a) Maintains authoritative name servers
b) Queries root DNS servers directly
c) Caches DNS responses for future use
d) Encrypts DNS queries for security
Answer: c) Caches DNS responses for future use
Which DNS record type is used for identifying the responsible party for a domain name, including contact information?
a) NS
b) SOA
c) TXT
d) RP
Answer: d) RP
What is the primary role of a root DNS server in the DNS hierarchy?
a) Resolves top-level domain (TLD) queries
b) Authenticates DNS queries for security
c) Manages DNS zone transfers
d) Encrypts DNS responses
Answer: a) Resolves top-level domain (TLD) queries
Which DNS record type is used for storing arbitrary text information associated with a domain name?
a) NS
b) SOA
c) TXT
d) RP
Answer: c) TXT
What does the ‘NS’ record stand for in DNS?
a) Network Service
b) Name Server
c) Node Security
d) Network Source
Answer: b) Name Server
Which DNS record type is used to provide additional information or comments in a DNS zone file?
a) A
b) SOA
c) PTR
d) ; (semicolon)
Answer: d) ; (semicolon)
What is the role of a stub resolver in DNS resolution?
a) Queries authoritative name servers directly
b) Provides recursive resolution for DNS queries
c) Maintains DNS zone files
d) Filters DNS queries based on content
Answer: a) Queries authoritative name servers directly
Which DNS record type is used for specifying the mail exchanger for a domain name?
a) A
b) MX
c) CNAME
d) PTR
Answer: b) MX