just for share

You own a single site, but several domains - perhaps you wanted
to make sure that even if your customers misspelled your domain
name they’d get to your site, or perhaps you’d like to have a
specific domain name direct to a page deep within your site -
whatever the case, there are some important considerations
surrounding multiple domain names routing to a single site and
search engine submission.

Search engines like Google and Yahoo won’t always wait around
for you to submit a site - Googlebot and Yahoo Slurp (which you
may recognize from your server logs if your site has been up for
a few weeks) are constantly running across new domain names to
index. It’s a good thing - unless your domain names are being
forwarded incorrectly.

What constitutes and incorrect forward?

Many major domain name registrars offer a “Domain Name
Forwarding” feature which, while it may be the easiest way to
forward your domain, can cause some real problems when search
engine spiders like Googlebot or Yahoo Slurp visit your site.

Here’s what happens:

1) The search engine spider pulls your domain name (usually from
http://www.whois.sc/ ) 2) The spider visits your website, using
the domain name forwarded through your domain registrar 3) Your
domain registrar is using a Temporary Redirect (most likely
because it’s assumed that you’ll point the domain name to a new
hosting account sooner or later), frames, or other incorrect
forwarding method 4) The spider indexes your site

But what went wrong? Your domain name registrar did its job, and
sent the spider to your actual site when it visited the domain
name you registered. The spider did its job and read the content
of the page or pages it found, and then incorporated them into
the search engine index. Everything’s copacetic, right?

When the search engine spider read the page, it associated it
with your alternate domain name, the one that was supposed to be
forwarding to your primary domain name. This means that the
search engine has effectively tracked down what it will quickly
identify as duplicate content - and, after years of dealing with
sites trying to sell Viagra on the sly by duplicating their
content across hundreds of pages, today’s search engines will
respond to duplicate content with a drop in your ranking.

Given enough time, you may find your site has been banned from
the search engine index.

What’s the solution?

Your domain names need to be routed from the domain name
registrar to a hosting account - from the hosting account (and
this varies - consult your technical support provider for the
account) you’ll need to set a Permanent Redirect to your main
site.

A Permanent Redirect is logged as a code ‘301′ (thence, it is
often referred to as a ‘301 Permanent Redirect’) - if you have
multiple domain names which you wish to direct to a single site,
it may be especially useful for you to consider a website
hosting account which offers multiple add-on domains and
subdomains to accommodate all the domain names you’ll need to
forward