DNS Changes and Multiple Domains

[weslinda]

Good afternoon everyone, I'm hoping to get some great feedback on how to handle an upcoming server change. (It's tomorrow)

What we're doing is moving a major web site to a new server, changing NameServers, and we have three domains that point to the information. Here are my questions.

What is the best way to avoid downtime of the site? Should we have our old DNS point to the new server IP and make the Name Server changes at the same time? Should we stutter step all of the changes?

Second, we eventually want to weed out all two of the three domains, mainly to improve our actual IBL count and to avoid duplicate content issues of course. What is the best way to slowly get out from under those domains?

Right now each actually have IBL's to our site, and not a small amount, so we need to slowly work to clean that up.

Is the best thing to do, point all three domains at the same content, then do a mod-rewrite or 301 redirect of the two domains we don't want to the one we do?

I want this to go smoothly so any help would be greatly appreciated.

[kgun]

1. Upload code to the new host.
2. Change DNS to point to that host's IP when finished.
3. When everything is OK, delete the old code.

Note in extreme cases, it may take up to 48 hours before the code / DNS is effective at the new host, but that is the exception. So be sure that the code functions properly at the new host (Ip) before you delete the old code. Change a word to see where it is effective and / or find the Ip of the domain. You must also be sure that the code is identical on the old and new IP. You may use a test server to test this thoroughly if it is a large site. That must be accertained before you change the DNS.

[Vectorman211]

What is the best way to avoid downtime of the site? Should we have our old DNS point to the new server IP and make the Name Server changes at the same time? Should we stutter step all of the changes?

Have your new DNS server up and ready to go (make sure you test it) and then change your NS ips to point to the new DNS server(s). You'll want to keep the old one running for a couple of days. As long as the actual host ips haven't changed DNS caching shouldn't be a problem.

Second, we eventually want to weed out all two of the three domains, mainly to improve our actual IBL count and to avoid duplicate content issues of course. What is the best way to slowly get out from under those domains?

Is the best thing to do, point all three domains at the same content, then do a mod-rewrite or 301 redirect of the two domains we don't want to the one we do?

I'll answer these 2 together. Just have all the domains point to the same content. If you're using apache:

<VirtualHost www.domain1.com>
DocumentRoot /home/www/html
</VirtualHost>

<VirtualHost www.domain2.com>
DocumentRoot /home/www/html
</VirtualHost>

<VirtualHost www.domain3.com>
DocumentRoot /home/www/html
</VirtualHost>

No need to use a 301 redirect. 301 is only useful if you move content to another URL so the search engines (and users) will note the change. If you're simply going to weed out those domains then this is the simplest way.[/code]