: Do I set a DNS A Record for the new GitHub Pages to use their CDN? GitHub updated their Pages service for custom domains yesterday and I'm not clear on one small detail. They recommend a

@LarsenBagley505

According to help.github.com/articles/tips-for-configuring-an-a-record-with-your-dns-provider/#configuring-a-www-subdomain

If you configure both an apex domain (e.g. example.com) and a matching www subdomain (e.g. example.com), GitHub's servers will automatically create redirects between the two.


Here is my setup that seems to work correctly:


in my DNS:


I've got a CNAME record for my-domain-name.com pointing to myusername.github.io
I've got an A record for my-domain-name.com pointing to 192.30.252.153 and 192.30.252.154

in my ghpages repo, my CNAME file contains my-domain-name.com

And this setup seems to work with Github's CDN.

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@Ann8826881

Do I use a CNAME for www only then, with no A record at all?


You would need to use a CNAME for the example.com subdomain, and an ALIAS record for your root domain example.com (aka., "apex domain").

As indicated in the help document you provided on Setting up a custom domain with Pages:


Some DNS providers (like DNSimple) allow you to use an ALIAS record to
point your custom apex domain to username.github.io. If your DNS
provider supports this it will allow us to provide the full benefits
of our Content Delivery Network to your Page.


Elaborating on this using their DNSimple reference, an ALIAS record is:


...a virtual record type that we created to provide CNAME-like
behavior on apex domains.

For example, if your domain is example.com and you want it to point to
a host name like myapp.herokuapp.com, then you cannot use a CNAME
record, but you can use an ALIAS record. The ALIAS record will
automatically resolve your domain to one or more A records at
resolution time and thus resolvers see your domain simply as if it had
A records.


The example DNSimple provides for setting an ALIAS record is here (substitute username.github.io for the Heroku server in that example).

For other DNS providers, see their support docs on how to set an ALIAS record to a subdomain. If your DNS provider does not support setting ALIAS records, then you'll have to use an A instead, which will not provide the benefit of GitHub's CDN.

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