Network Services Ch12

How do DNS servers know how to find the DNS root name servers? (short answer)

DNS servers are preconfigured with the IP addresses of the root name servers

What DNS server is never the authoritative source for a domain, but only serves to resolve names? a. Root name server b. Forwarder c. Caching-only server d. Authoritative source

c. Caching-only server

What is the benefit of name caching? (short answer)

it allows the second name resolution request to not have to go through the referral process

Regarding DNS servers, what is the authoritative source for any domain responsible for? (short answer)

it is responsible for maintaining the resource records associated with that domain

In Domain Name System, a name resolution request in which the DNS server immediately responds with the best information it possesses at the time.

iterative query

The ability of a DNS server to retain information about names that do not exist in a domain

negative caching

In the Domain Name System, the process by which the server hosting the primary zone copies the primary master zone database file to the secondary zone so that their resource records are identical.

zone transfer

A DNS server receives updated information. Other DNS servers have outdated information cached. What determines the amount of time that the old DNS data remains cached on a server and an update might occur? a. Time To Live (TTL) specified by each DNS server's administrator b. Network congestion between DNS servers c. The version of Windows Server on the DNS server d. The distance (number of network hops) between the new information and queried DNS server

a. Time To Live (TTL) specified by each DNS server's administrator

Why is the DNS service included in Windows Server 2012 integrated with DHCP service? a. To allow a DHCP server to request a DNS server to update or create a record. b. To update both DNS and DHCP clients with information from the Active Directory. c. To allow a DNS server to inform DHCP clients with updated information. d. DNS and DHCP services are not integrated in Windows Server 2012.

a. To allow a DHCP server to request a DNS server to update or create a record.

You registered the domain name helix.com. The FQDNs seattle.helix.com and halifax.helix.com are examples of different _____. a. subdomains of halifax.com b. top-level domains c. second-level domains d. IP addresses

a. subdomains of halifax.com

What DNS server is responsible for maintaining a particular domain's resource records? a. Root name server b. Forwarder c. Authoritative source d. Caching-only server

c. Authoritative source

What is the character limit on individual domain names, and the limit on the Fully Qualified Domain Names (FQDNs)? a. 15; 64 b. 63; 255 c. 31; 128 d. 63; 128

b. 63; 255

What client applications utilize DNS to resolve host names into IP addresses? (Select best answer) a. DNS does not resolve host names into IP addresses. b. All Internet applications working with host names must use DNS to resolve host names into IP address. c. Any application on a system that has connectivity to the Internet uses DNS to resolve host names into IP addresses. d. Client web browsers, or any application that uses HyperText Transfer Protocol (HTTP), use DNS to resolve host names into IP addresses.

b. All Internet applications working with host names must use DNS to resolve host names into IP address.

What do you call the source responsible for maintaining a domain's resource records? a. Authenticate source b. Authoritative source c. Down-level server d. Root server

b. Authoritative source

What are some best practices when creating internal DNS namespaces? (Select best answer) a. Never abbreviate. b. Avoid an excessive number of domain levels. c. Keep domain names full and descriptive; avoid concise subdomains. d. Place less importance on a convention compared to spelling.

b. Avoid an excessive number of domain levels.

What DNS server normally sends recursive queries to another DNS server? a. Caching-only server b. Forwarder c. Authoritative source d. Root name server

b. Forwarder

Who is responsible for the ratification of new top-level domains? a. Network Solutions, Inc. (NSI, formerly known as InterNIC) b. Internet Corporation for Assigned Names and Numbers (ICANN) c. Internet Assigned Numbers Authority (IANA) d. Contoso.com

b. Internet Corporation for Assigned Names and Numbers (ICANN)

Concerning DNS, what is negative caching? a. When a DNS server receives obsolete information about a host b. When a DNS server receives information about a non-existent host c. When a DNS server receives incorrect information about a host d. When a DNS server forwards incorrect information about a host

b. When a DNS server receives information about a non-existent host

The domain name part of a DNS name is _______ and consists of two or more words, separated by ______. a. hierarchical; commas b. hierarchical; periods c. unranked; commas d. peer-based; periods

b. hierarchical; periods

You type a web address in your web browser. Order the steps, which describe the Internet name resolution process for the web address. Write your answer using letters separated by commas. a. Client's DNS server, with the top-level domain server address, generates a new iterative query and sends it to the top-level domain server. The top-level domain server responds with a referral to the second-level domain server. b. Client's DNS server checks records for authoritative source for the zone containing the web address. DNS server sends iterative query to a root server. Root server responds with referral to top-level domain server address. c. Client system sends a recursive query message with the web address to the DNS server as specified in the system's TCP/IP configuration. d. Client's DNS generates another iterative query and transmits it to the second-level domain server. Assuming second-level server is authoritative server for the zone containing the web address, it consults its records to determine IP address of requested system, and then messages back to the client's DNS server. e. Client's DNS receives reply from the authoritative server and transmits the IP address back to the client. The client's web browser now knows the IP address of the web server.

c, b, a, d, e

When using DNS for name resolution only, why should a company consider using DNS servers outside the network perimeter? a. Fewer servers in the communications server rack b. Less administration c. Less traffic crossing the network perimeter d. Less internal traffic

c. Less traffic crossing the network perimeter

What are the servers at the top of the DNS hierarchy called? a. Authoritative sources b. Forwarders c. Root servers d. Down-level servers

c. Root servers

The typical query one DNS server sends to a root name server is called a(n) _______. a. recursive query b. iterative query c. referral d. forwarded query

c. referral?

How does a caching-only server differ from a normal DNS server? (short answer)

caching-only servers are used to resolve names while normal DNS servers are authoritative sources for domains

Concerning DNS domain hierarchy, what are examples of global top-level domains? a. .aero, .name, .pro b. .ca, .cz, .kr c. .mil, .gov, .edu d. .com, .net, .org

d. .com, .net, .org

What is the default TTL for a Windows Server 2012 DNS server? a. 36 hours b. 12 hours c. 5 minutes d. 1 hour

d. 1 hour

At what level of the DNS hierarchy are actual hosts, apart from the root servers? a. At the root servers level b. At the top-level domain level c. At the third-level domain level d. At the second-level domain level

d. At the second-level domain level

What is the primary purpose of name caching? (Select best answer) a. Name caching validates why you should deploy caching-only servers. b. Name caching saves an extraordinary amount of time for the user. c. Name caching greatly reduces traffic on the company network. d. Name caching enables the second name resolution request for the same name to bypass the referral process.

d. Name caching enables the second name resolution request for the same name to bypass the referral process.

What is the primary benefit of a DNS forwarder? (Select best answer) a. Exchanging iterative queries for recursive queries across the network perimeter b. Reducing the burden on the Internet's root name servers c. Making the most of iterative queries to other DNS servers d. Reducing the traffic and making efficient use of available bandwidth across the network perimeter

d. Reducing the traffic and making efficient use of available bandwidth across the network perimeter

What DNS server represents the top of the DNS hierarchy? a. Caching-only server b. Forwarder c. Authoritative source d. Root name server

d. Root name server

When a DNS server communicates a name resolution query to another DNS server, what type of datagram is used, and over what port? a. UDP; 35 b. TCP; 53 c. TCP; 35 d. UDP; 53

d. UDP; 53

When a DNS server communicates a large zone transfer to another DNS server, what type of datagram is used, and over what port? (short answer)

datagram: TCP port: 53

In Domain Name System, a name resolution request in which the DNS server takes full responsibility for resolving the name. If the server has no information about the name, it sends referrals to other DNS servers until it obtains the information it needs.

recursive query

In the Domain Name System, a client program that generates DNS queries and sends them to a DNS server for fulfillment.

resolver

In the Domain Name System, the process by which a server converts an IP address into a DNS name.

reverse name resolution