Computer Networks Multiple Choice Questions on “DNS”.
1. The entire hostname has a maximum of ___________
a) 255 characters
b) 127 characters
c) 63 characters
d) 31 characters
Answer: a
Clarification: An entire hostname can have a maximum of 255 characters. Although each label must be from 1 to 63 characters long. Host name is actually a label that is given to a device in a network.
2. A DNS client is called _________
a) DNS updater
b) DNS resolver
c) DNS handler
d) none of the mentioned
Answer: b
Clarification: DNS client also known as DNS resolver also known as DNS lookup helps to resolve DNS requests using an external DNS server.
3. Servers handle requests for other domains _______
a) directly
b) by contacting remote DNS server
c) it is not possible
d) none of the mentioned
Answer: b
Clarification: Whenever a request is received at server from other domains, it handles this situation by contacting remote DNS server.
4. DNS database contains _______
a) name server records
b) hostname-to-address records
c) hostname aliases
d) all of the mentioned
Answer: d
Clarification: Domain Name system not only deals with mapping IP addresses with the hostname but also deals with exchange of information in the server.
5. If a server has no clue about where to find the address for a hostname then _______
a) server asks to the root server
b) server asks to its adjcent server
c) request is not processed
d) none of the mentioned
Answer: a
Clarification: Root name servers are actually very important and critical as they are the first step in translating human readable hostnames into IP addresses for carrying out communication.
6. Which one of the following allows client to update their DNS entry as their IP address change?
a) dynamic DNS
b) mail transfer agent
c) authoritative name server
d) none of the mentioned
Answer: a
Clarification: Dynamic DNS or in short DDNS or DynDNS helps in automatically updating a name server in the DNS. This does not require manual editing.
7. Wildcard domain names start with label _______
a) @
b) *
c) &
d) #
Answer: b
Clarification: A wildcard DNS record matches requests to a non existent domain name. This wildcard DNS record is specified by using asterisk “*” as the starting of a domain name.
8. The right to use a domain name is delegated by domain name registers which are accredited by _______
a) internet architecture board
b) internet society
c) internet research task force
d) internet corporation for assigned names and numbers
Answer: d
Clarification: The ICANN (Internet Corporation for Assigned Names and Numbers) deals with IP address space allocation, protocol identifier assignment, generic and country code Top Level domain name system management (gTLD and ccTLD).
9. The domain name system is maintained by _______
a) distributed database system
b) a single server
c) a single computer
d) none of the mentioned
Answer: a
Clarification: A domain name system is maintained by a distributed database system. It is a collection of multiple, logically interrelated databases distributed over a computer network.
10. Which one of the following is not true?
a) multiple hostnames may correspond to a single IP address
b) a single hostname may correspond to many IP addresses
c) a single hostname may correspond to a single IP address
d) none of the mentioned
Answer: c
Clarification: It need not be that a single hostname will correspond to a ip address. For example facebook.com and fb.com both correspond to same ip address. So there can be multiple hostnames for a single ip address.