Route53 Flashcards
What is DNS?
Used to create human-friendly website names to IP addresses.
What are the two different common forms of IP?
IPv4 - 32 bit field which has over 4 billion addresses. A signal grain of sand for each would fill up a dump truck.
IPv6 - 128 bit field which has 340 undecillion addresses. A signal grain of sand for each would fill up the sun.
When looking at domain names, what is the top level domain vs the second level domain?
The top level domain is the last word in the domain name. The second level, if there is one, is the word before that
- cnn.com - top level: .com; no second level
- bbc.co.uk - top level: .uk; second level: .co
True or False. Elastic Load balancers never have a pre-defined IPv4 address. You resolve them using a DNS name.
True.
What are common DNS types? List 6
- SOA Records
- NS Records
- A Records
- CNAMES
- MX Records
- PTR Records
True or False. You cannot buy domain names with AWS.
False, you can.
True or False. It can take up to 5 days to register a domain depending on the circumstances.
False, it can take up to 3 days.
What is a simple routing policy?
Only have one record with multiple IP addresses. If you specify multiple values in a record, Route 53 returns all values to the user in random order.
What is weighted routing policy and how does it work?
Allows you to split your traffic to different regions of the world, depending on the percentages you’ve created.
What is latency based routing and how does it work?
Route 53 determines which is the routing policy with the lowest latency (fastest response time) and then sends the user to that server.
What is failover routing policy and how does it work?
You choose an active and passive server. When the active fails a healthcheck, it fails over to the passive server.
What is geolocation routing policy and how does it work?
Based on where the DNS for the customer shows them, the routing policy will route the customer to the necessary EC2 in the correct region.
What is a multivalue answer policy and how does it work?
Allows you to configure Route 53 to return multiple values, such as IP addresses for your web serves, in response to DNS queries. Basically simple routing policy with the ability for a healthcheck.
What is the difference between an Alias Record and a CNAME?
Alias record directly links, the CNAME uses a lookup to reference the link. The primary difference between a CNAME record and an ALIAS record is not in the result—both record types point to another DNS record—but in how they resolve the target DNS record when queried. In short, one (ALIAS record) is safe to use at the zone apex (ex. naked domain, such as example.com) and the other is not.
You have created a new subdomain for your popular website, and you need this subdomain to point to an Elastic Load Balancer using Route53. Which DNS record set should you create?
- A
- CNAME
CNAME