Tuesday, October 30, 2007

The DNS Host Is Crucial For A Custom Domain

When you setup your Google Custom Domain, the instruction for the DNS addressing setup is rather basic.
Add one or more "A" and / or "CNAME" records. Point "www.mydomain.com", and / or "mydomain.com", to "ghs.google.com", or to a series of Google servers.

Unfortunately, all DNS hosts don't provide multiple "A" referrals / "CNAME" referral to "ghs.google.com"; some only allow for a conventional "A" referral to a single, fixed IP address.

These instructions are most often seen when you purchase the domain directly from a third party registrar, and your registrar sets up the domain itself - since when you use "Buy a domain", all of this detail is done for you.

There are thousands of registrars, all over the world, willing to sell you name registration. Not all registrars can provide the right DNS hosting service.

Of those hosts that do support the former
Point "www.mydomain.com" to "ghs.google.com".
not all can support the latter.
Point "mydomain.com" to "ghs.google.com".


If StartLogic is your DNS Host, you're out of luck. See the note in the top panel?
Primary domains (domain.com) can only be routed to a valid IP address.
StartLogic only allows direction of the primary domain ("root") to an IP address ("A" referral), not to a host ("CNAME" referral).



Yet the ability to refer the primary domain is the key to successful use of the Custom Domain, as many bloggers find out. Some bloggers have, in the past, tried various workarounds like domain forwarding, which is simply not a good idea. It's possible that a server based 301 Redirect, setup properly, may accomplish this for the primary domain, if used as the secondary URL for the blog. It won't substitute for a "CNAME" referral for the "www" alias (or another alias of your choice), when used as the primary URL for the blog, though.

You have 3 - and only 3 - choices, when setting up your domain.
  1. A Symmetrical DNS configuration requires 2 x "CNAME" referrals, 1 for the domain root, the other for the "www" alias.
  2. An ASymmmetrical DNS configuration requires 4 x "A" referrals for the domain root, and a "CNAME" referral for the "www" alias.
  3. A Non Root Virtual Host DNS configuration requires a single "CNAME" referral, for the specific single host alias.
You will need one, or the other, for a reliable custom domain. Understand the monolithic rigid requirements, for the DNS addresses - and be prepared to emphasise the requirements to the tech support contacts, when you ask your registrar for help.

And now, with the addition of a second "CNAME" to verify domain ownership, the choice of registrars becomes even more important. Not every registrar will let you setup 2 "CNAME"s in any given domain or sub domain - and not every registrar will allow long "Destination" / "Target" / "Points To" addresses. If your current registrar won't allow the necessary second "CNAME", or long "Destination" / "Target" / "Points To" addresses, you'll have to move the domain to another registrar - the second "CNAME" is neither frivolous nor optional.

If you don't see any instructions in the documentation provided by your DNS Host, maybe you should contact technical support. Generally when you pay for service, and in many cases when you don't (such as with Blogger), there is a technical support staff somewhere. In many cases, a cooperative and knowledgeable support staff is another essential here.

There is no substitute for a correctly setup "A" / "CNAME" referral, at least for an alias in your domain. If your DNS host won't support the latter, or a server based 301 Redirect, you need a better registrar. You have two and a half alternatives now.
  1. Stay with this registrar, and use another DNS host, such as ZoneEdit.
  2. Transfer the domain to another registrar, such as one of the two Blogger partner registrars.
  3. If your primary URL is setup, and pointing to a domain alias, and the problem is simply not being able to use the primary domain for the secondary URL, maybe you can refer the primary domain through Google Apps.


A properly setup Google custom domain starts with a carefully chosen DNS host / registrar. That's the bottom line.

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16 comments:

testblog said...

do i have to do anything with the A host ip address????? the people at go daddy said i might need to change this to get it to work. do you know what i would change it to?
steve

Chuck said...

Steve,

With GoDaddy Total DNS Control, you have 2 lists - "A" and "CNAME". The "A" list needs to be empty, and the "CNAME" for the "www" alias needs to be at the top of the "CNAME" list.

That's how my two domains are setup.

Wilson said...

i have this domain www.sexonocinema.com

how to redirect sexonocinema.com to www.sexonocinema

Chuck said...

Wilson,

You have to have either an explicit "CNAME" for "sexonocinema.com", or an implied one.

Right now, it looks like you have an "A" record referring "sexonocinema.com" to "208.109.181.91". That won't work.

C:\>ping sexonocinema.com

Pinging sexonocinema.com [208.109.181.91] with 32 bytes of data:

Reply from 208.109.181.91: bytes=32 time=36ms TTL=56
Reply from 208.109.181.91: bytes=32 time=35ms TTL=56
Reply from 208.109.181.91: bytes=32 time=37ms TTL=56
Reply from 208.109.181.91: bytes=32 time=36ms TTL=56

Ping statistics for 208.109.181.91:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 35ms, Maximum = 37ms, Average = 36ms

C:\>ping www.sexonocinema.com

Pinging ghs.l.google.com [66.249.81.121] with 32 bytes of data:

Reply from 66.249.81.121: bytes=32 time=70ms TTL=246
Reply from 66.249.81.121: bytes=32 time=73ms TTL=246
Reply from 66.249.81.121: bytes=32 time=75ms TTL=246
Reply from 66.249.81.121: bytes=32 time=70ms TTL=246

Ping statistics for 66.249.81.121:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 70ms, Maximum = 75ms, Average = 72ms

Proverbs said...

hi,

Could this be explained ? i didnt get this right.

With GoDaddy Total DNS Control, you have 2 lists - "A" and "CNAME". The "A" list needs to be empty, and the "CNAME" for the "www" alias needs to be at the top of the "CNAME" list.

That's how my two domains are setup.

Regards,
Jacob.

Chuck said...

Jacob,

What you're describing sounds right. What domain and what BlogSpot blog are we looking at?

Wilson said...

Thanks chuck !

The answer is make a new record, with only "." !


Proverb, i have a godaddy registration, and you only need create a record with "."

Chuck said...

Wilson,

Using the "." is syntactically, and technically, correct. But, it's not consistent for all GoDaddy DNS servers, nor can you find a GoDaddy person to explain this. I believe that customers of other DNS hosting services have experienced the same inconsistency.

Dan Gustafson said...

Have deleted A records in Godaddy. wayzata.blogspot.com works, cannot get it to work at www.wayzata.com.

Any suggestions or advice?

Chuck said...

Dan,

Have you posted already in GBH: How Do I?, and I missed the post? If so, my apologies. But the online forums are much easier to use, then Blogger Blog Commenting, for interactive problem solving.

Dan Gustafson said...

Hi Chuck,

I have not posted there, but searched for answers for some time. Don't see anything as compelling or informational as what I see at your blog.

Chuck said...

Dan,

I'm flattered. But neither "compelling" nor "informational" are the issues. It's simply easier to conduct a 2 way conversation using the forums, which will help us solve your problem quicker.

Ghodmode said...

Hi Chuck,
I understand that the ideal setup has the "A" record and a "CNAME" record (like "www", for example) both pointing to "ghs.google.com". Did I get that right?

In this article you said that one solution would be to use GoDaddy as the registrar. I'm using GoDaddy but, from what I can tell, they only allow IP addresses with "A" records. How does using GoDaddy as my registrar provide a solution?

You mention 4 Google (Apps?) servers by IP address in other articles, but I'm uncomfortable using those because they're not documented by Google and could be changed or brought down at any time.

Currently, I have my "www" alias pointing to "ghs.google.com" and "@" as an "A" record pointing to GoDaddy's forwarding server IP address (64.202.189.170). I've set up GoDaddy's forwarding to send requests for my domain to the "www" alias with a 301 redirect. In another article, you identified this as a bad idea. Since it's not pointing at a single Google server, why is this a problem?

Everything's working right now, but I do have the "The DNS record for your domain is not set up correctly yet." message in the Publishing settings for my blog. Searching for information about that message led me to your blog.

Here are my dig results:
ghodmode.com. 3600 IN A 64.202.189.170
www.ghodmode.com. 3600 IN CNAME ghs.google.com.
ghs.google.com. 330898 IN CNAME ghs.l.google.com.
ghs.l.google.com. 142 IN A 74.125.53.121

Thank you.

--
-- Vince

Chuck said...

Ghodmode,

You need to post in GBF: How Do I?. The online forums are much easier to use, then Blogger Blog Commenting, for interactive problem solving.

The 4 "A" servers are what you get, when you use "Buy A Domain", and they're what everybody uses, when they know what they are doing. Argue this in the forum, please.

khush said...

I'm kinda having a problem with the site where I tried to register my
newly bought and registered domain "http://www.niksgadget.in".

They're not providing any way to control the DNS settings of my
domain, just nameserver boxes which, according to them, will point to
where my blog is hosted.

I gave them the "ghs.google.com" provided in the blogger help but they
said it's not a valid nameserver.
my blog url is http://ideals4all.blogspot.com

Is there anyone who can help me about this?

Chuck said...

Khush,

You have apparently purchased domain registration, without getting DNS hosting.