Here at DNSimple we really strive to push ahead of the curve to offer all of our customers the latest and best features in Domain Name Management. Recently we added the awesome CAA record and we have an upcoming beta of full DNSSEC support.
However sometimes the standard record set doesn't cover everyone's use cases. This is why we have created some of our own custom records to help simplify some common needs and tasks our users encounter. Each of these records do actually translate down into standard records and requests with a bit of DNSimple magic on the back end, but to you it's just as easy as putting in a single record. I thought I would take the time not just to list those records, but also explain some good ways they can be used.
The ALIAS record is one of our more popular custom records for good reasons. One of the biggest limitations of DNS that most people hit is that the apex of your domain, example.com for this example, cannot be an CNAME record. However with more and more people dropping the www from domain names in order to simplify them, this restriction causes problems with pointing your records to many different providers. This often causes people to have to set up a lot of weird hacks or make their configuration fragile.
With the ALIAS record it's easy to point example.com to my-cool-app.herokudns.com. In the background, DNSimple will handle the internal resolution and point my apex example.com to the right A record each time.
Often we end up buying additional domains besides your primary domain. It's a good idea to buy similar domain names just to have coverage, and if you end up changing over to a new, cooler domain name, you will definitely want to keep your old one around for a quite a while. This is where the URL record really shines.
Setting up a redirect server can be a lot more of a hassle than most people want, but you want your old domains to 301 redirect properly to your new cooler domain. The URL records lets us take on all the setup of your simple 301 redirects. Now you can set up exampleblog.com URL example.com/blog
While the POOL record is one of the least common custom records, it's not the least powerful at all. In fact, when you have the use case, it's a blessing. Another technical limitation of DNS records is that you cannot have more than one CNAME at any hostname like you can with an A records. POOL records lets you create a pool of CNAME records for any subdomain, and on our side we will round robin through those records, always returning just one of the CNAME records.
The power of POOL records really comes for things like static content hosting with different CDN resources, letting you balance between multiple resources. Now it's not hard to set up css.static.example.com to css-example-com.akami.com as well as static-example.cloudflare.com and use both at the same time.
I hope this overview not only has offered an explanation of how these records work but some of the best usecases for these. If you want more information please make sure to check out our support site or send us an email.