Domain Names
Hosted in AWS Route 53
There are 3 hosted zones, one for the top level domain and one for each subdomain.
ichrisbirch.com Hosted Zone
This is referred to as the Apex domain, or top level domain.
There are 5 records in this hosted zone:
| Record Name | Type | Description | Value |
|---|---|---|---|
| ichrisbirch.com | NS |
Created automatically with the hosted zone | AWS Apex Nameservers |
| ichrisbirch.com | SOA |
Created automtaically with the hosted zone | AWS DNS |
| api.ichrisbirch.com | NS |
Nameservers from hosted zone NS record |
AWS API Nameservers |
| docs.ichrisbirch.com | CNAME |
Re-direct from Github Pages to docs subdomain | datapointchris.github.io |
| \www.ichrisbirch.com | A |
Points to the EC2 IP of the webserver | EC2 IP (Elastic IP) |
api.ichrisbirch.com Hosted Zone
There are 3 records in this hosted zone:
| Record Name | Type | Description | Value |
|---|---|---|---|
| api.ichrisbirch.com | A |
Points to the EC2 IP of the webserver | EC2 IP (Elastic IP) |
| api.ichrisbirch.com | NS |
Created automatically with the hosted zone | AWS Api Nameservers |
| api.ichrisbirch.com | SOA |
Created automtaically with the hosted zone | AWS DNS |
docs.ichrisbirch.com Hosted Zone
There are 3 records in this hosted zone:
| Record Name | Type | Description | Value |
|---|---|---|---|
| docs.ichrisbirch.com | A |
Points to the EC2 IP of the webserver | Github Servers |
| docs.ichrisbirch.com | NS |
Created automatically with the hosted zone | AWS Docs Nameservers |
| docs.ichrisbirch.com | SOA |
Created automtaically with the hosted zone | AWS DNS |
Refer to the Documentation and CICD pages for setting up Github Pages with this subdomain.
Use dig {address} to see if the domain looks set up correctly.
Danger
If the DNS seems to not be updating and the records are not working, be wary of the Browser Cache and history!!
Safari kept the old IP in the cache until restart, the only way to see the update was to use a Private Window
Check the cache before troubleshooting.
Apex - ichrisbirch.com ( www.ichrisbirch.com )
There should be a nameserver record created with the hosted zone, and the soa is created automatically.
The A record should point to the elastic IP if assigned, or public ip of the instance or load balancer and the name should have subdomain www. I believe because the domain ichrisbirch.com is the apex, it doesn't need an A record.
api.ichrisbirch.com
There should be a nameserver record created with the hosted zone and soa, same as the Apex.
The A record should point to the elastic IP.
There should be another NS record with the API Nameservers that is attached to the Apex zone.
This allows the Apex to know how to discover the subdomain.
docs.ichrisbirch.com
The docs are slightly different because they are hosted by github, being served with mkdocs, so they are not sitting on the server like the app (www) and api (api) are.
There should be the similar NS and soa records created.
The A record points to the github (I think) hosts where the docs are hosted:
CNAME record lives at the Apex level, in place of the NS records like the api uses.Since the
CNAME is an alias, it is used to alias docs.ichrisbirch.com => datapointchris.github.io
Reference
1. NS (Name Server) Records
Purpose: NS records specify the authoritative name servers for a domain. These servers hold the DNS records for the domain. Function: Direct traffic by telling DNS resolvers which nameserver(s) to ask for the specific domain’s information. Usage: Found at the domain's DNS zone and commonly points to multiple nameservers to provide redundancy. Example:
2. SOA (Start of Authority) Records
Purpose: SOA records provide essential information about the DNS zone of a domain, including the primary nameserver, the admin’s contact email, and timing information for zone transfers. Function: Defines the authoritative server and sets the rules for DNS caching, zone transfers, and DNS record updates. Usage: Should be the first record in a DNS zone file, as it contains critical operational data. Example:
example.com. IN SOA ns1.example.com. hostmaster.example.com. (
2023010101 ; Serial
7200 ; Refresh
3600 ; Retry
1209600 ; Expire
3600 ; Minimum TTL
)
3. A (Address) Records
Purpose: A records map a domain or subdomain to an IPv4 address. Function: Translates the human-readable domain names to numerical IP addresses that computers use. Usage: Essential for pointing a domain or subdomain to a web server’s IP address. Example:
www.example.com. IN A 192.0.2.1
4. CNAME (Canonical Name) Records
Purpose: CNAME records alias one domain name to another. Function: Points one domain/subdomain to another domain/subdomain, allowing management of multiple addresses by changing a single target address. Usage: Useful for pointing multiple subdomains to a single canonical name and to reduce redundancy in DNS management. Example:
blog.example.com. IN CNAME www.example.com.
How They Relate to Domains and Subdomains
NS Records: Define which servers are authoritative for the domain's DNS records. If you have subdomains, the NS records for the main domain affects them unless specifically overridden.
SOA Records: Hold administrative information and control parameters for the DNS zone; they are vital for overall DNS zone health and updates.
A Records: Directly tie domain names and subdomains to specific IP addresses. Different subdomains can be mapped to different IPs using A records.
CNAME Records: Allow you to point subdomains (or even the root domain if needed) to other domain names, simplifying DNS management. For example, blog.example.com can point to www.example.com, which has an A record, thereby inheriting its IP indirectly.
Example Application: For a domain example.com:
- NS Records: Point to ns1.example.com and ns2.example.com.
- SOA Record: Contains administrative details for the DNS zone, like contact info and timing settings.
- A Record: Points
www.example.comto 192.0.2.1. - CNAME Record: Points blog.example.com to
www.example.com, which has the A record for the actual IP.
AWS Documentation
Routing traffic for subdomains - Amazon Route 53Routing traffic for subdomains - Amazon Route 53