Network Content Delivery pt2

What is a domain registrar?

An organization or service through which you register a domain name

What is a DNS record?

A rule or entry that provides information about a domain or hostname

What is a DNS zone file?

A file containing DNS records for a DNS zone

What is a name server?

A server that provides DNS information for a domain or zone

What is a Top-Level Domain (TLD)?

The final domain label, such as .com, .org, .gov, or .us

What is a Second-Level Domain (SLD)?

The domain label immediately to the left of the TLD in a typical domain such as amazon.com

Which statement best describes the difference between a hostname and an IP address?

A hostname is a human-readable name; an IP address identifies a network endpoint for communication

What is the primary purpose of a recursive DNS resolver?

To perform DNS lookups on behalf of clients and return answers, often using cached results

What is an authoritative name server?

A server that provides authoritative DNS data for a zone

What is a Route 53 hosted zone?

A collection of DNS records for a domain or DNS namespace

Which statement about public and private hosted zones is correct?

Private hosted zones are intended to resolve names within associated VPCs

What does the Time to Live (TTL) field control in a DNS record?

How long a DNS answer can be cached before it should be queried again

Which fields are commonly associated with a standard Route 53 record?

Domain or subdomain name, record type, value, routing policy, and TTL

What does an A record do?

Maps a hostname to an IPv4 address

What does an AAAA record do?

Maps a hostname to an IPv6 address

What does a CNAME record do?

Maps a hostname to another hostname

What does an NS record identify?

The name servers associated with a DNS zone or delegation

A company owns example.com and wants to create a development hostname, dev.example.com. Which action should it take if the development hostname should resolve to an IPv4 address?

Create an A record for dev.example.com with the development server's IPv4 address in the appropriate hosted zone

An engineer visits https://api.example.com/v1/orders?status=open. Which part is the hostname that DNS resolves?

api.example.com

A company registers example.com with GoDaddy but wants Amazon Route 53 to manage its DNS records. Which statement is correct?

The company can keep GoDaddy as registrar and configure the domain to use the appropriate Route 53 name servers

A DNS resolver has cached an A record with a TTL of 300 seconds. The company updates the record to a new IP address. What should the engineer expect?

Resolvers that cached the old answer may continue using it until their cache entry expires

A company wants to resolve database.internal.example.com only from applications in its associated VPCs, not from the public internet. Which Route 53 configuration is most appropriate?

A private hosted zone associated with the relevant VPCs

A web server is reachable at IPv4 address 192.0.2.25. The company wants app.example.com to resolve directly to that address. Which record should it create?

A

A service has IPv6 address 2001:db8::25. Which DNS record type should map ipv6.example.com to this address?

AAAA

A company wants www.example.com to point to app.example.net without storing the destination IP address in the www.example.com record. Which record type best fits this requirement?

CNAME

A company wants to configure a CNAME record for example.com, the root of its DNS namespace. Route 53 rejects the configuration. What is the reason?

A CNAME cannot be used at a zone apex because the apex must coexist with required records such as SOA and NS

A company wants to identify the authoritative name servers for its hosted zone. Which record type should the engineer inspect?

NS

An engineer is configuring example.com to direct DNS queries to a separately managed subdomain zone called dev.example.com. Which configuration supports delegating that subdomain?

Create an NS record for dev.example.com that identifies the child zone's name servers, and configure the child hosted zone appropriately

A Route 53 record contains the name app.example.com, type A, value 192.0.2.25, routing policy Simple, and TTL 60. What does the value represent?

The IPv4 address returned by the record

A company is moving an application to a new server IP address and wants DNS resolvers to cache the answer for a shorter period during the transition. Which record setting should it adjust?

TTL

A company runs two application endpoints and wants Route 53 to send approximately 80% of DNS traffic to one endpoint and 20% to the other. Which routing policy is most appropriate?

Weighted routing

A global application has endpoints in multiple AWS Regions. The company wants users directed to the endpoint expected to provide the lowest network latency. Which routing policy should it consider?

Latency-based routing

A company has primary and secondary endpoints and wants Route 53 to return the primary under normal conditions and the secondary when the primary is unhealthy. Which routing policy best fits this requirement?

Failover routing

A company wants to return different DNS answers depending on the geographic location from which a DNS query originates. Which routing policy should it consider?

Geolocation routing

A company wants Route 53 to return multiple healthy endpoint values for a DNS query and use health checks to help exclude unhealthy endpoints. It does not need the weighted percentages of weighted routing. Which policy is most appropriate?

Multivalue answer routing

What part of the URL is http://?

Protocol

What part of the URL is api.www?

Sub Domain

What part of the URL is example?

SLD (Second-Level Domain)

What part of the URL is com?

TLD (Top-Level Domain)

What part of the URL is the dot (.) at the very end?

Root