Web Hosting or DNS

It is common sense that if a web site is down it cannot get spidered, but we’ll state it regardless:
When a site is down, it cannot get spidered.And when your domain’s designated DNS is down, your
site cannot get spidered either — even if your web server is up. Reliable hosting and DNS, then, is
critical to your web site’s well-being. A web site that is down will irritate users and result directly
in fewer users visiting your web site. It may also reflect badly on your business, and users may not
be back. Likewise, if a search engine spider visits your web site and it does not respond after quite
a few unsuccessful attempts, it may result in your web site getting dropped from the index. For
this reason we recommend cutting costs elsewhere.

Most of the time, users opt to use a web hosting provider’s DNS. This may be wise, because they may
need to alter DNS records in order to move you to another server with another IP if the server your
web site is located on fails. However, domain providers (Network Solutions, GoDaddy, and so on)
have more recently begun to offer free managed DNS services as well. If you use managed DNS,
the hosting provider will not be able to change your domain’s records to reflect the new IP, and
your site will be down as a result. For this reason, we do not recommend using managed DNS
unless your provider is aware of it, and knows to notify you, so that you can change the records
yourself to reflect the new IP.

Hosting Providers

Should the need exist to change hosting providers, the process must be completed in the proper order.
Not doing so may result in a time window where your site is unreachable; and this is clearly not desirable,
from both a general and SEO perspective. The focus of this elaborate process is to prevent both users and
search engines from perceiving that the site is gone — or in the case of virtual hosting, possibly seeing the
wrong site.
Virtual hosting means that more than one web site is hosted on one IP. This is commonplace,
because the world would run out of IPs very quickly if every web site had its own IP. The problem
arises when you cancel service at your old web hosting provider and a spider still thinks your site
is located at the old IP. In this case, it may see the wrong site or get a 404 error; and as you suspect,
this is not desirable.
The proper approach involves having your site hosted at both hosting providers for a little while. When
your site is 100% functional at the new hosting provider, DNS records should then be updated.

Functionality was also used to set up the seophp.example.comdomain. On Windows machines,
the file is located in C:\WINDOWS\system32\drivers\etc\hosts.
Add the following lines:
xxx.xxx.xxx.xxx www.yourdomain.com
xxx.xxx.xxx.xxx yourdomain.com
This will let you access your web site at the new provider as if the DNS changes were already reflected.
Simply remove the lines after you are done setting up the site on the new web hosting provider’s server
to verify the changes have actually propagated.
If you have concerns about this procedure, or you need help, you may want to contact your new hosting
provider and ask for assistance. Explain your concerns, and hopefully they will be able to accommodate
you and put your mind at ease. If they are willing to work with you, it is a good indication that they are
a good hosting provider.

MSN Search has a useful feature that allows you to see all virtual hosts on one IP by the syntax of
IP:xxx.xxx.xxx.xxx. Multiple statements can be separated by ORto request a list of a range of IPs.
This lets you see who else is hosting in a range. Spam tends to travel in packs. Search engine algorithms are also aware of this. The fact that the operator exists may be a tacit admission by Microsoft
that it does examine the sites in an IP range for some reason.