What happens if 301 redirected domain is taken down?

[DFul4d]

Will the site loose its transferred link popularity if the domain that is being redirected is taken down? Or is the transfer permanent after several months? Any ideas?

[Relevancy]

I have gone through this myself with some sites. Once the redirect is in place and indexed several times you should be able to safely remove the 301. The PR should be transfered.

[Jill Whalen]

Relevancy, I'm curious. How can you tell that?

[Chris_D]

301 = Moved permanently.

For a Get request, a 301 is defined as:

The requested resource has been assigned a new permanent URI and any future references to this resource SHOULD use one of the returned URIs

http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

i.e the instruction to robots is don't request the 'old' URL in future - request the new one.

Obviously - taking down the 'old' domain & therefore taking down the 301 redirection won't help returning human visitors who have bookmarked the 'old' site - but thats a different issue

[Relevancy]

Yeah, what he said.

[Jill Whalen]

Right, but the robots follow links, and if there's still links to the old URL, they'd now be getting a 404 not a 301.

Do you really think they store somewhere in their memory that the site had permanently moved? (I have no idea, I'm really asking.) It sounds a bit hard to imagine.

Would love to hear from someone who has programmed search engines before on this one. I personally just leave my 301's up, but this is an interesting question more out of curiousity than anything else. I just can't imagine how it would still work if the site no longer existed and there was no 301. Doesn't intuitively make sense to me.

[Chris_D]

Do you really think they store somewhere in their memory that the site had permanently moved? (I have no idea, I'm really asking.) It sounds a bit hard to imagine.

Jill - what's the Pagerank concept mean? Where does that information get stored? What does the 301 tell the search engine to do?

The 301 tells a robot that future references to this resource SHOULD use one of the returned URIs i.e the permanently moved to address.

Once its indexed that information - its done.

[DFul4d]

Leaving the domain up is not an option, unless we go to court

[Jill Whalen]

Well, then you will get to tell us first hand what happens! Please do come back in a few months and let us know either way.

[Robert_Charlton]

Originally Posted by Jill Whalen

Right, but the robots follow links, and if there's still links to the old URL, they'd now be getting a 404 not a 301....

That's what I think too. I've got 301s I've kept up for years because there are some good inbounds I can't get changed.

Originally Posted by Chris_D

Jill - what's the Pagerank concept mean? Where does that information get stored? What does the 301 tell the search engine to do?

The 301 tells a robot that future references to this resource SHOULD use one of the returned URIs i.e the permanently moved to address.

Once its indexed that information - its done.

Chris_D - Doesn't make sense to me. What about re-indexing? I've had pages that lose PageRank because the linking site has disappeared or converted to Flash navigation or whatever, so I know PR isn't forever. I can't believe a remembered 301 would be either. I'm very curious about this one.

[WebGuerrilla]

If a bot stops getting a 301 when it requests urls it finds on the web, the PR transfer will go away. If you are losing control of a domain, you should 301 it as soon as you can, and then work hard to get all the good links switched to your new domain before you lose control.

Regarding the concept of "leaving the old site up," you don't need to do that. The 301 you set up should be on the new site. Just create an A record in your dns pointing to the IP of the new domain. Then add the 301 to the .htaccess file of your new domain. When a bot comes to the new site using the old domain, it will get the 301.

[Jill Whalen]

Thank you Greg! I assume you've seen this first hand?

That's exactly how I would imagine it, just knowing how search engines work, but without ever trying it or seeing it first hand, I had no way to know.

Thanks for clearing up the confusion here.