ALIAS Record

The ALIAS record is a type of DNS record that is used to point one domain name (or subdomain) to another domain. It’s similar in purpose to the CNAME record but can coexist with other records on the domain’s apex (or root), which CNAME records cannot.

Key Characteristics of ALIAS Records:

  1. Purpose: The ALIAS record provides a way to overcome the limitations of the CNAME record, particularly its inability to be set at the domain apex alongside other records.
  2. Functionality: When the DNS system is queried for a domain with an ALIAS record, the authoritative DNS server resolves it directly to the IP address of the target domain rather than returning the target domain’s name (as CNAME would). This resolution is done in real-time.
  3. Example:
   example.com.  IN  ALIAS  anotherdomain.com.
  1. Usage: Useful when you want to point the root of your domain (e.g., example.com) to a cloud platform, Content Delivery Network (CDN), or another service where the actual IP addresses may change frequently.

Advantages:

  • Domain ApexOne of the primary benefits of the ALIAS record is the ability to point the apex of a domain to another domain, something that CNAME records can’t do.
  • CoexistenceUnlike CNAME, an ALIAS record can coexist with other DNS records for the same domain.
  • Real-time ResolutionALIAS records provide real-time resolution to the IP address of the target domain, ensuring that even if the target domain’s IP address changes, the ALIAS record will always resolve to the current IP.

Considerations:

  • Provider Support: Not all DNS providers support ALIAS records. It’s essential to check whether your DNS hosting provider offers this type of record if you intend to use it.
  • Resolution Overhead: Because the ALIAS record requires the DNS provider to perform a real-time resolution of the target domain, there might be a slight increase in DNS lookup times compared to traditional records.

In essence, the ALIAS record provides a valuable tool for modern web infrastructure setups, especially when utilizing cloud services or CDNs that require flexible DNS configurations.

Key terms in plain language

Open a term for a concise explanation of language used on this page.

Cloud Computing

Computing resources—such as applications, servers, storage, or databases—delivered from remote infrastructure and scaled as requirements change.

Content Delivery Network (CDN)

A distributed system that serves website or application content from locations closer to users, improving speed, resilience, and capacity.

Infrastructure as a Service (IaaS)

Cloud-based servers, storage, and networking that customers configure and manage without owning the underlying data-center hardware.

Software as a Service (SaaS)

Software accessed as an online service instead of being installed and maintained entirely on the customer’s own computers or servers.

Disaster Recovery (DRaaS)

A plan and service for restoring applications, data, and operations after an outage or disruption. DRaaS provides recovery infrastructure through a managed cloud service.

Identity and Access Management (IAM)

The systems and policies that determine who a user is, what resources they may access, and how that access is authenticated and reviewed.