Chris Linfoot | 302, pagejacking and Domino

Friday, 12. October 2007

302, pagejacking and Domino

Update: We are now on a D8 server here. The redirect from www.chris-linfoot.net to chris-linfoot.net is now a 301 permanent redirect.

Try this little test.

Hover over this link, and watch the status bar in your browser while you do. You should see a URL pointing at www.chris-linfoot.net/...

Now click that link.

Where did you end up?

You ended up right back here, at a page whose URL contains no "www." I do this because, despite the fact that this site is at chris-linfoot.net, many people still insist on adding a redundant www when referring to pages here.

How is this implemented?

DNS for www.chris-linfoot.net points to the same place as DNS for chris-linfoot.net
The Domino server hosting the site has an additional web site document defined for www.chris-linfoot.net and that document has the same home URL as chris-linfoot.net
In addition, there is a single redirection rule in place for that www... site, which redirects /* to http://chris-linfoot.net/*

So far, so good. Is there a problem with this?

Well, yes. And no.

If you have access to Sam Spade or a similar tool which allows you to examine HTTP headers, use it to open www.chris-linfoot.net. You should see this:

Fetching http://www.chris-linfoot.net/ ...
GET / HTTP/1.1
Host: www.chris-linfoot.net
Connection: close
User-Agent: Sam Spade 1.14

HTTP/1.1 302 Found
Server: Lotus-Domino
Date: Fri, 12 Oct 2007 09:51:06 GMT
Connection: close
Location: http://chris-linfoot.net/

Note that response - HTTP/1.1 302 Found.

This is a moved temporarily response and it is frowned upon by SEO experts * the world over.

The reason for the prevailing view among SEO experts * that 302 redirects are a bad thing is that, a few years ago, Google was vulnerable to an exploit called "pagejacking" (and do, please, note carefully both my use of the past tense in the foregoing sentence and the date on the linked piece, which is briefly quoted below).

Google has a nasty bug these days that allows unsavory webmasters to hijack the content on your site. If your competitor wants to destroy your search engine rankings he only needs to create a simple page that forces a HTTP 302 redirect to your site. Sounds harmless enough right? Well the problem is that Google follows the redirect to the your site but gives the evil redirect site credit for the content.

Yes, in days of yore Google could be persuaded to give a hostile webmaster the entire credit for your site's content, simply by following a 302 redirect from a domain under the control of that hostile webmaster to your site - this is pagejacking in a nutshell.

So, what's the problem?

Firstly, let's deal with the issue of pagejacking. Google dealt with that ** a long time ago and it simply is no longer an issue. No other major search engine was ever vulnerable.

But...

Under Domino 6 and 7 (and probably 5 though I have no means of verifying this) there is no way of varying the behaviour of redirects - Domino redirects are always 302 (temporary), even where (as is the case here) the redirection is permanent and 301 would be a more appropriate response.
SEO experts * still consider 302 undesirable and list it at the top of the executive summary page of their report into why your company's expensive new web site has tanked on Google. This gives you grief you really don't need.

There's good news, though.

For Domino 6 and 7 sites that use redirects, pagejacking is a thing of the past and you are not vulnerable, even if your expensive SEO expert * says you are.
For Domino 8 sites, we have a new feature that was quietly slipped in when no-one was looking.

Domino 8 allows the use of 301 permanent redirects

Don't bother checking this box if you are in a mixed version environment with a D8 Domino Directory, but your web server is still on a D7 server. If your server is on D8, though, you can finally get those pesky SEO experts * off your case for good.

* I use the term experts with considerable regret.
** The latest update in that bug tracking page is dated 18 Sep 2006 and declares the issue "close to" fixed.

Category: T'Internet
Technorati: 302 Google pagejacking