Overview of DNS Requirements for Google App Engine Applications

Question

I have a Google App Engine running and I bought a domain. To link the two, I followed the official guide .

In particular, management suggests setting up these DNS rules:

The fact is that I have both a bare domain (site.com) and a subdomain www (www.site.com). Following the guide, I set the following rules:

Type      Name               Value
A         site.com.          216.239.32.21
A         site.com.          216.239.34.21
A         site.com.          216.239.36.21
A         site.com.          216.239.38.21
(other AAAA for site.com.)
CNAME     www.site.com.      ghs.googlehosted.com

Questions

I think I did it right because it works: I can dial site.com and www.site.com and be redirected to my application. But I have some confusion regarding the www subdomain.

• What is ghs.googlehosted.com and why do I need a CNAME for the www subdomain? Why are there no A entries for www?

• ? A , CNAME, IP.

• , :

. , , - www ghs.googlehosted.com. ( , @ .)

? @?

Answer 1

DNS, A AAAA (IPv6) CNAME.

1) A AAAA www. DNS

A         www.site.com.          216.239.38.21
(other AAAA for site.com.)

2) , www , www.site.com → ghs.googlehosted.com. , www. site.com

CNAME     www.site.com.      ghs.googlehosted.com

3) @ . , @, .com.

, DNS. , , www.

CNAME     www.site.com.      ghs.googlehosted.com
CNAME     @      ghs.googlehosted.com

.

CNAME     www.site.com.      site.com
CNAME     @      ghs.googlehosted.com

www .