App Engine Domain CNAME Record - "ghs.google.com" or "ghs.google.com."

Question

I'm not too experienced with DNS records and I'm trying to point a www subdomain to Google App Engine via the registrar gandi.net.

When updating the CNAME record to direct traffic to ghs.google.com, is it critical that there be a period at the end of ghs.google.com in the zone file?

Currently the raw zone file line looks like this:

www 3600 IN CNAME ghs.google.com.

Thanks!

Kimkimball

Answer 1

Yes, you need to have the trailing dot.

You enter the entire hostname followed by a period when the hostname is not inside your domain. Since google is outside your domain, you need the "extra" dot.

For example (using example.com as our domain), with the trailing dot, the CNAME would redirect to ghs.google.com. Without the trailing dot, we'd end up atghs.google.com.example.com, which isn't what you want.

Tove

Thanks, exactly the explanation I was looking for. – Kimkimball

Most DNS admin tools add the tailing DOT by themselves nowadays. Nevertheless it is a good habit to write it. It's like the preceding slash in /file/paths/and/names – Ultra