Route 53 Flashcards
What does DNS stand for?
Domain Name System
What does DNS do?
Translates domain names into IP addresses.
What is a Top-Level Domain (TLD)?
The last segment of the domain, e.g., .com, .org.
What is a Second-Level Domain (SLD)?
The domain directly before the TLD, e.g., amazon.com.
What is Route 53?
AWS’s scalable and highly available authoritative DNS service.
Why is Route 53 called that?
53 is the port number used by DNS.
What are common DNS record types?
A, AAAA, CNAME, NS
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 is an NS record?
Specifies the name servers for a hosted zone.
What is a hosted zone in Route 53?
A container for DNS records defining routing rules for a domain.
What is TTL in Route 53?
Time to Live – how long DNS records are cached.
When to use high TTL?
Less traffic to Route 53 but possibly outdated records.
When to use low TTL?
Frequent updates and faster propagation of changes.
What is the difference between CNAME and Alias?
CNAME can’t be used for root domains; Alias can and is free.
Can Alias records be used at root domain level?
Yes.
Can you set TTL for Alias records?
No, Route 53 manages it automatically.
What are common targets for Alias records?
ELB, CloudFront, API Gateway, S3 websites, Route 53 records.
Can you use Alias records for EC2 DNS?
No.
What does a simple routing policy do?
Routes to a single resource or randomly among multiple.
What is a weighted routing policy?
Distributes traffic across resources by assigned weights.
Can weighted records have health checks?
Yes.
What is latency routing?
Routes traffic to the region with the lowest latency.
What is failover routing?
Routes traffic to a secondary resource if the primary is unhealthy.
What is geolocation routing?
Routes based on user’s physical location.
What is geoproximity routing?
Routes traffic based on proximity and bias (expand/shrink).
What is multi-value answer routing?
Returns multiple healthy resources, up to 8.
What is Route 53 Traffic Flow?
A visual tool to manage complex routing configurations.
What is a calculated health check?
Combines multiple health checks using logical operations.
What is a CloudWatch alarm health check?
Monitors metrics like RDS or custom values for health.
How does Route 53 perform health checks?
Using HTTP/HTTPS/TCP from multiple global checkers.
What status codes mean a successful health check?
2xx and 3xx.
What is the interval for health checks?
Default 30s; can be 10s (at extra cost).
Can health checks check private resources?
Yes, using CloudWatch alarms.
What is a domain registrar?
A service to buy and register domain names.
Can you use Route 53 with third-party domains?
Yes, by updating NS records to Route 53’s servers.
