Route53

Managed DNS

Route53 can USE:

· Public domain names you own (or buy)

· private domain names that can be resolved by your instances in your VPCs

Route53 has Advanced Features such as:

· load Balancing (through DNS - also called client load balancing)

· Health Checks (although limited )

· pay 50 cents per month per hosted Zone

· CNAME vs ALIAS

o AWS Resources (Load Balancer and Cloudfront etc) expose asn AWS URL lb12-1234.ap-southeast-2-elb.amazonaws.com and you want it to be myapp.mydomain.com

o CNAME

§ Points an URL to any other URL

§ Only for NonRoot Domain , Zone Apex (aka something.mydomain.com)

o ALIAS

§ Points an URL to an resource only. (myapp.mydomain.com -> something.amazinaws.com)

§ Works for both Root and Non Root domain (aka mydomain.com )

§ free of charge

§ Native health checks

Routing Policies

· Simple

o one record can point to multiple IP addresses, where if multiple addresses are entered in the record, any of the addresses are returned in random order.

· Weighted

o Add each record separately with a particular weight; Route53 then apportions the record set appropriately

o can have health check

· Latency

o Routes to lowest latency for the user

· Failover

o Primary and Secondary records in the set. i.e. Active / Passive

o Health check fails

· Geolocation

o Route based on user Geolocation

§ Geoproximity Routing Policy (Traffic Flow Only)

Ø Route based on users and resources

Ø Introduce bias (extend or shrink a region)

Ø

· Multi Value

o similar to Simple Routing Policy but has health checks

o Use when routing Traffic to multiple resources

o Want to associate health-checks with Records

o up to 8 healthy records are returned with each Muti-Value query

o Multi-Value is not a substitute for having an ELB

A Route Origin Authorization (ROA) is a document that you can create through your Regional internet registry (RIR), such as the American Registry for Internet Numbers (ARIN) or Réseaux IP Européens Network Coordination Centre (RIPE). It contains the address range, the ASNs that are allowed to advertise the address range, and an expiration date. Hence, Option 3 is the correct answer.

The ROA authorizes Amazon to advertise an address range under a specific AS number. However, it does not authorize your AWS account to bring the address range to AWS. To authorize your AWS account to bring an address range to AWS, you must publish a self-signed X509 certificate in the RDAP remarks for the address range. The certificate contains a public key, which AWS uses to verify the authorization-context signature that you provide. You should keep your private key secure and use it to sign

DNS > CNAME point to subdomain | Alias can point to apex | CNAME is a Canonical Name Record or Alias Record that specifies that one domain name is an alias of another canonical domain name.

A Record is used to point a logical domain name, such as "google.com", to the IP address of Google's hosting server, "74.125.224.147".

Private DNS Route53 > Private hosted Zone with dns resolution

the authorization-context message.

DNS records consist of;

-A (address record) the IP address eg; 192.168.0.1

-AAAA (IPv6 address record)

-CNAME (canonical name record)

-CAA (certification authority authorization)

-MX (mail exchange record)

-NAPTR (name authority pointer record)

-NS (name server record)

-PTR (pointer record) ; ised for reverse lookup , i.e opposite of "A" record

-SOA (start of authority record)

-SPF (sender policy framework)

-SRV (service locator)

-TXT (text record)