This article was previously published under Q168322
SUMMARY
This explains why a Domain Name Service (DNS) Alias record is needed, and
how to create it.
MORE INFORMATION
Sometimes it is useful to be able to access a server (or any host) by using
a name other than its DNS host name.
For example, you have an Application Server whose DNS configuration is as
follows:
Host Name Domain Name
--------- -------------
myserver mydomain.com
You have also setup your server as a WWW server so Internet or Intranet
browsers can access Web pages from it. You want people to access your Web
server by specifying www.mydomain.com as its name instead of
myserver.mydomain.com.
To accomplish this, an alias (or canonical name) record needs to be added
to your DNS server.
The DNS server should already have the following record under the
mydomain.com zone (IPAddress should be the IP address of your server):
Myserver A <IPAddress>
The following record should be added to the mydomain.com zone:
www CNAME myserver.mydomain.com
When a DNS server looks up a name and finds a "CNAME" record, it replaces the
name with the canonical name, and looks up the new name, in this case,
www.mydomain.com.