Don't quite get Domain Mapping. Using DirectAdmin panel.

Update summary:

• IP-type WDM (WordPress Domain Mapping) might not work with DirectAdmin.
• CNAME-type WDM always works, presumably. Anyway, I have it working.
• Howto: Enom -> yourcustomdomain.com -> Edit Host Records -> Host name: WWW … Record type: CNAME … Address: yourmultisitewordpress.com … And/or (not sure which is better) … Host name: * … Record type: CNAME … Address: yourmultisitewordpress.com. (“DNS Settings” also must be set to “Enom servers.” No custom nameservers. Also do not use “@” for CNAMEs.)

The details:

1. After two days of trying everything, IP-type WDM was not working for my DirectAdmin-powered server with the WDM in “primary” mode. (Super Admin: Domains: Primary-YES.) Then Explorer just keeps spinning its wheels. Firefox seems more intelligent and says, “Redirection loop,” or, “Firefox has detected that the server is redirecting the request for this address in a way that will never complete.”
2. Non-primary IP-type WDM works fine for me. However, this results in the custom domain disappearing from the browser bar, and thus, the sub-site never being accepted as a unique domain. This makes the custom domain rather pointless. (No pun intended.)
3. However, contrary to a previous statement by me, with DirectAdmin, “create as alias” is needed for IP-based WDM to work at all. (After deleting or creating this “alias,” it just may take some minutes for the difference to take effect.) Otherwise with Primary-NO, the custom domain only forwards to the Home page. And as explained above, when the WDM setting is Primary-YES, then apparently some “redirection loop” results.
4. I barely understand these matters. I can only surmise that “maybe” DirectAdmin has nothing precisely equal to Cpanel’s “domain parking” which is in the official WDM instructions. DirectAdmin instead has “domain pointing” with “create as alias” as an option.
5. define( ‘SUNRISE’, ‘on’ ); has been placed to the second-last line in my wp-config.php, just above require_once and somewhat below “do not edit below.” The Otto tutorial mentions no precise placement. However the official WDM instructions seem to imply that this exact placement is important, so that’s what I did.
6. I re-installed WordPress using Dashboard: Updates. Also turned off the Weaver template and reverted to the default Twenty Ten. No effect.
7. After two days of frustration, I finally tried CNAME redirection. Success! Otto’s tutorial seems to assume that IP redirection is best for most cases. However the official WDM instructions list several benefits, and no serious problem, for CNAME redirection. Other than this, no tutorial was clear about whether to enter the CNAME at the registrar or at the server…? For the source domain or for the target domain…? And what precisely to enter for each column…? After some reading in Wikipedia, it seemed “most likely” I should enter the CNAME at my registrar (Enom) for the source domain, as detailed above.

Additional notes:

• Both Enom and the WDM instructions warn not to use “@” for a CNAME.
• I suspect that the asterisk (*) entry above might be unnecessary and perhaps even problematic…? Also, with this configuration, when I enter http://www.BrattleboroBuffet.com, the www is stripped. I am uncertain if this is good or bad, but am still experimenting. Any tips are welcome…?
• For CNAME redirection, my DirectAdmin “pointer” for BrattleboroBuffet.com has been deleted.
• DirectAdmin also create CNAME and other DNS options for the “pointer” of BrattelboroBuffet.com. This was not tried and I don’t know anything about it. In general, for a serious website, one is certainly supposed to set up “custom nameservers,” and not to use Enom’s “public nameservers” which are less efficient. Setting up CNAME records at Enom requires retaining Enom’s “public nameservers.” But on the other hand, bouncing off of DirectAdmin’s “pointing” seems equally indirect…? On balance, a multi-site hosting of a WordPress blog probably should never be expected to be as efficient as a primary website, no matter what…
• So, I am happy to stay with CNAME-redirection. However, I would be slightly happier to know “if” IP-redirection is somehow possible with DirectAdmin…? Any tips would be welcome.
• Another interesting possibility: “Domain Mapping Without Plugins,” May 2010. This might be slightly more direct than either IP or CNAME redirection with WDM. However Andrea prefers using the WDM plug-in, “as the included sunrise.php files helps with letting WP know you have some mapped domains before the rest fires up.”

Andrea, thank you for clarifying the problems with the non-plugin method!

For myself, the problem is solved. (Mostly.) But I feel the need to point out, for my future reference or readers who (like me) do not clearly understand anything about DNS, some potential ambiguities.

1. My problem might have been that, instead of IP records, I was doing NS records. (ns1.verhampshire.com etc.) Because…
–This is the way I usually set up websites.
–This was what I was told to do at WordPress.com.
–I did not think there was much difference. (But maybe there is.)

2. It seems to me that, if using the CNAME method, nothing needs to be done at the server. This immediately points the name BrattleboroBuffet.com -> Verhamsphire.com. End of story. In my experience, the WMD plug-in settings will take over from there.

3. Finally, maybe the problem is that with DirecAdmin, “pointing” a domain automatically creates a series of server-level A records. These can be deleted.

4. Nonetheless, with both Otto and Andrea saying that IP is usually nicer than CNAME… I tend to believe there are reasons…! So, here are my current experiments in order of priority:

(a) Try again with Enom “custom nameservers” (ns1.Verhampshire.com etc.). Delete the server-level A records generated by DirectAdmin when “pointing.” (DirectAdmin -> User Level -> Advanced: Domain Pointers -> after creating pointer, if WMD is not working, click “manage” to experiment.) Also, if the WMD setting for IP vs. CNAME makes any difference, this also is another possibility. Perhaps with ns1.nameservers, CNAME should be designated for WMD…?
(b) If that fails… Revert to Enom nameservers. Then use Enom -> Host Records -> IP numbers. As seems to be recommended by Andrea. (Once again, after “pointing,” if this fails, I will try deleting those DirectAdmin server-level A records.)
(c) If all else fails, Enom -> Host Records -> BrattleboroBuffet.com: CNAME: Verhampshire.com. Works for sure, and for me, no pointing or parking is needed.

(If all this sounds ignorant, well what do you expect from the ignorant? If by chance anyone wants the exact results of these bumbling tests, please reply here. Otherwise, I won’t reply again. I do have it working. Just trying to make it better. Thank you Andrea and Ipstenu!)