Route53
Basics
- Provides domain registration
- Provides Domain Name System (DNS)
- Service health checks
- Supported formats
- A (Address)
- IPv4 address
- AAAA Format
- IPv6 address
- CNAME
- same format as domain name
- Alias resource record sets
- Route 53 supports alias resource record sets, which enables routing of queries to a CloudFront distribution, an Elastic Beanstalk, an ELB, an S3 bucket configured as a static website, or another Amazon Route 53 resource record set
- MX (Mail Xchange)
- NS (Name Server)
- PTR Format
- SOA (Start of Authority)
- SPF (Sender Policy Framework)
- SRV Format
- TXT (Text) Format
- Supports following routing policies
- Simple
- Weighted
- Latency
- Failover
- Geolocation
Limits
- CNAME DNS protocol doesn't allow creation of CNAME record for the zone page for example google.com, but CNAME can be created for www.google.com, search.google.com etc.
- If CNAME record is created for www.google.com, no other resource record for subdomains (where the value of Name field is www.google.com) can be created.
Basically
- Do not create CNAME record for naked domain alias (zone apex)
- CNAME alias can be used for most cases (AWS Services)
Following topics are exam questions collected through Internet and should be evaluated as so. Answers are mine and have been checked with answers collected through the internet, but might still be wrong.
Does Amazon Route 53 support NS Records?
A. Yes, it supports Name Service records.
B. No
C. It supports only MX records.
D. Yes, it supports Name Server records.
Why? https://aws.amazon.com/route53/faqs/ "Which DNS record types does Amazon Route 53 support? Amazon Route 53 currently supports the following DNS record types: NS (name server record)"
Does Route 53 support MX Records?
A. Yes.
B. It supports CNAME records, but not MX records.
C. No
D. Only Primary MX records. Secondary MX records are not supported.
http://docs.aws.amazon.com/Route53/latest/DeveloperGuide/ResourceRecordTypes.html#MXFormat
A US-based company is expanding their web presence into Europe. The company wants to extend their AWS infrastructure from Northern Virginia (us-east-1) into the Dublin (eu-west-1) region. Which of the following options would enable an equivalent experience for users on both continents?
A. Use a public-facing load balancer per region to load-balance web traffic, and enable HTTP health checks.
B. Use a public-facing load balancer per region to load-balance web traffic, and enable sticky sessions.
C. Use Amazon Route 53, and apply a geolocation routing policy to distribute traffic across both regions.
D. Use Amazon Route 53, and apply a weighted routing policy to distribute traffic across both regions.
Which of the following statements are true about Amazon Route 53 resource records? Choose 2 answers
A. An Alias record can map one DNS name to another Amazon Route 53 DNS name.
B. A CNAME record can be created for your zone apex.
C. An Amazon Route 53 CNAME record can point to any DNS record hosted anywhere.
D. TTL can be set for an Alias record in Amazon Route 53.
E. An Amazon Route 53 Alias record can point to any DNS record hosted anywhere.
Why? http://docs.aws.amazon.com/Route53/latest/DeveloperGuide/resource-record-sets-choosing-alias-non-alias.html "A CNAME record can point to any DNS record hosted anywhere" & "another resource record set in the same Amazon Route 53 hosted zone in which you're creating the alias resource record set. "
A customer is hosting their company website on a cluster of web servers that are behind a public-facing load balancer. The customer also uses Amazon Route 53 to manage their public DNS. How should the customer configure the DNS zone apex record to point to the load balancer?
A. Create an A record pointing to the IP address of the load balancer
B. Create a CNAME record pointing to the load balancer DNS name.
C. Create a CNAME record aliased to the load balancer DNS name.
D. Create an A record aliased to the load balancer DNS name
Why? https://support.dnsimple.com/articles/differences-between-a-cname-alias-url/
http://docs.aws.amazon.com/elasticloadbalancing/latest/classic/using-domain-names-with-elb.html
For Create Record Set, do the following:
How can the domain’s zone apex, for example, “myzoneapexdomain.com”, be pointed towards an Elastic Load Balancer?
A. By using an Amazon Route 53 Alias record
B. By using an AAAA record
C. By using an Amazon Route 53 CNAME record
D. By using an A record
Why? https://aws.amazon.com/route53/faqs/
"Q. Can I point my zone apex (example.com versus www.example.com) at my Elastic Load Balancer?
Yes. Amazon Route 53 offers a special type of record called an ‘Alias’ record that lets you map your zone apex (example.com) DNS name to your ELB DNS name (i.e. elb1234.elb.amazonaws.com). IP addresses associated with Amazon Elastic Load Balancers can change at any time due to scaling up, scaling down, or software updates. Route 53 responds to each request for an Alias record with one or more IP addresses for the load balancer. Queries to Alias records that are mapped to ELB load balancers are free. These queries are listed as “Intra-AWS-DNS-Queries” on the Amazon Route 53 usage report." Notable is also that CNAME records are charged whereas Alias is free.
A. Use a public-facing load balancer per region to load-balance web traffic, and enable HTTP health checks.
B. Use a public-facing load balancer per region to load-balance web traffic, and enable sticky sessions.
C. Use Amazon Route 53, and apply a geolocation routing policy to distribute traffic across both regions.
D. Use Amazon Route 53, and apply a weighted routing policy to distribute traffic across both regions.
Which of the following statements are true about Amazon Route 53 resource records? Choose 2 answers
A. An Alias record can map one DNS name to another Amazon Route 53 DNS name.
B. A CNAME record can be created for your zone apex.
C. An Amazon Route 53 CNAME record can point to any DNS record hosted anywhere.
D. TTL can be set for an Alias record in Amazon Route 53.
E. An Amazon Route 53 Alias record can point to any DNS record hosted anywhere.
Why? http://docs.aws.amazon.com/Route53/latest/DeveloperGuide/resource-record-sets-choosing-alias-non-alias.html "A CNAME record can point to any DNS record hosted anywhere" & "another resource record set in the same Amazon Route 53 hosted zone in which you're creating the alias resource record set. "
A customer is hosting their company website on a cluster of web servers that are behind a public-facing load balancer. The customer also uses Amazon Route 53 to manage their public DNS. How should the customer configure the DNS zone apex record to point to the load balancer?
A. Create an A record pointing to the IP address of the load balancer
B. Create a CNAME record pointing to the load balancer DNS name.
C. Create a CNAME record aliased to the load balancer DNS name.
D. Create an A record aliased to the load balancer DNS name
Why? https://support.dnsimple.com/articles/differences-between-a-cname-alias-url/
- The A record maps a name to one or more IP addresses, when the IP are known and stable.
- The CNAME record maps a name to another name. It should only be used when there are no other records on that name.
- The ALIAS record maps a name to another name, but in turns it can coexist with other records on that name.
- The URL record redirects the name to the target name using the HTTP 301 status code.
http://docs.aws.amazon.com/elasticloadbalancing/latest/classic/using-domain-names-with-elb.html
For Create Record Set, do the following:
- Leave the default name, which is the name of your domain.
- For Type, select A — IPv4 address.
- For Alias, choose Yes. An alias enables Amazon Route 53 to associate your domain name with an AWS resource, such as a load balancer.
How can the domain’s zone apex, for example, “myzoneapexdomain.com”, be pointed towards an Elastic Load Balancer?
A. By using an Amazon Route 53 Alias record
B. By using an AAAA record
C. By using an Amazon Route 53 CNAME record
D. By using an A record
Why? https://aws.amazon.com/route53/faqs/
"Q. Can I point my zone apex (example.com versus www.example.com) at my Elastic Load Balancer?
Yes. Amazon Route 53 offers a special type of record called an ‘Alias’ record that lets you map your zone apex (example.com) DNS name to your ELB DNS name (i.e. elb1234.elb.amazonaws.com). IP addresses associated with Amazon Elastic Load Balancers can change at any time due to scaling up, scaling down, or software updates. Route 53 responds to each request for an Alias record with one or more IP addresses for the load balancer. Queries to Alias records that are mapped to ELB load balancers are free. These queries are listed as “Intra-AWS-DNS-Queries” on the Amazon Route 53 usage report." Notable is also that CNAME records are charged whereas Alias is free.
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