Alias records are meant to simulate a CNAME record for A record queries anywhere in a zone, but are most commonly placed at the Apex of a zone. Alias records are not enabled by default. Contact Dyn Technical Support to review the requirements for adding Alias to your zone.
Placing a CNAME record at the apex of a zone is not currently supported by the Domain Name System (DNS), per RFC 1912. Putting an Alias record at the apex of a zone allows you to present a “naked domain” (e.g. https://example.com instead of “https://www.example.com”) when using a cloud provider like Amazon Web Services (AWS).
It is important to note the following about ALIAS records:
- As ALIAS is not a standard DNS record, Alias records CANNOT be used in conjunction with Traffic Manager (TM), Real Time Traffic Manager (RTTM), or GeoTraffic Manager services. Alias records can be used with Traffic Director but monitoring capabilities will be lost.
- Alias records cannot be transferred to a secondary DNS provider via an AXFR/IXFR transfer.
- Zones that contain Alias will also have DNSSEC records added. If you attempt to AXFR transfer or download a zone file that contains Alias, there will be DNSSEC signatures present, even if DNSSEC is not enabled. The ALIAS service uses DNSSEC signatures to carry the payload data to understand current IP addresses of the redirect servers. DNSSEC signatures are only used for this purpose, and are not inserted for every record of the zone.
- There are some considerations when utilizing Alias that points to a CDN, namely:
- If the end point of your Alias record has hundreds of possible IP addresses, like a CDN does, you are relying on the vantage point your DNS provider is observing. This reduces your overall footprint from your CDN provider to that of the vantage of your DNS provider.
- Some CDN’s will use our Anycast network (the locations that are resolving your Alias record) to determine geolocation instead of the source IP. This further limits the geolocation services of your CDN. See the Dyn Anycast DNS Network Map for more information.
- It is recommended that you use a fallback entry on the node where your ALIAS record exists in the form of A, AAAA, or an HTTP redirect service. ALIAS records take precedence over A and AAAA records and HTTP redirect services on the node they reside on. If we encounter an error resolving the FQDN for your ALIAS record, we will instead serve out A and AAAA records on this node, or an HTTP redirect service to avoid serving no record in a response.
How to Add an Alias Record
Mapping Alias for Geo-locational DNS
If you intend to point an Alias record at a geo-locational aware DNS service, you will want to ensure that your provider has the correct Dyn addresses of where your Alias record will be served.
|Ashburn, VA, US||18.104.22.168/27|
|Chicago, IL, US||22.214.171.124/27|
|Palo Alto, CA, US||126.96.36.199/27|
|Hong Kong, China||188.8.131.52/27|
|Newark, NJ, US||184.108.40.206/27|
|Dallas, TX, US||220.127.116.11/27|
|Los Angeles, CA, US||18.104.22.168/27|
|Miami, FL, US||22.214.171.124/27|
|Seattle, WA, US||126.96.36.199/27|
|Sao Paolo, Brazil||188.8.131.52/27|