should I use A or CNAME?

DNS confuses me

[savetz]

Despite having been on the Internet forever and making Web sites for half that time, I still don't quite understand DNS. I have two situations and would appreciate advice. My main concern in both situations is not losing Google PageRank.

Situation 1: I am transitioning a site from stupiddomainname.info to betterdomainname.com. It has been suggested to me that the best way to do that is to make betterdomainname.com a CNAME to the server for a few months. Then, after users and the serarch engines are used to the new name, switch, making it the A (canonical) name and stupiddomainname.info the CNAME. Is that a good way to do it?

Situation 2: I have a site, widgetinfo.com, with a good PageRank. I've recently acquired sprocketinfo.com which I want to point to the same site. But I don't want to somehow harm the PageRank of widgetinfo.com, when Google notices two identical sites. If someone searches the Web for "widget information", I would prefer theit hits say widgetinfo.com not sprocketinfo.com. So - does it matter if sprocketinfo.com is a CNAME or a A record? Or should I just use my ISP's domain forwarding service?

Thanks

[bakedjake]

Situation 1: No, that won't work. What you want to do is do a 301 redirect from olddomain.info to newdomain.com. Make sure they are hosted on seperate IP addresses. Then, you want to take the next couple of months and get links changed (and/or developed) from olddomain.com to newdomain.com.

A CNAME will serve the same content on different domains, and could look bad. At best, it'll have undesirable consequences.

Situation 2: Host sprocketinfo.com on a seperate IP than widgetinfo.com. Do a 301 redirect from sprocketinfo to widgetinfo. Google will figure it out properly.

[savetz]

Thank you for the information, bakedjake.

Would it matter in situation 2 if I use 302 instead of 301? (It would end up being less expensive. Don't ask.)

[bakedjake]

It is best if you do a 301, but as long as you don't do link development towards sprocketinfo.com, you could get away with a 302.

[jeepfun]

If you are going to keep both domains, why not have them route to the same place and then put a URL rewrite rule on the server to rewrite to the domain name that you like better. Seems much cleaner to me.

Put the A record on the domain you care about most and move everything else to a cname of it.

Just my thoughts.
Vinny