The shortest name available in a dns domain is known as the zone apex, naked domain or bare name. For example, example.com is the shortest name for the example.com domain.
Conventional usage on the internet is that web sites appear at two names although they are the same site. For the domain example.com, users would expect to be able to reach the web site at both:
Many sites will use a http redirect mechanism to concentrate their traffic at one name or the other. The reasons may be operational simplicity, branding or search engine optimisation. The redirection can be done on the server itself, or through an external service such as the edgedirector http redirection service. With a redirection in place, the site can concentrate on one name without leaking visitor traffic.
However, sites which use managed cloud services such as Amazon Web Services or Microsoft Azure, blog hosting services such as wordpress.com and blogger.com, or content distribution networks are often limited to dns CNAME records. This requirement is usually in place to allow the services to be provided from multiple servers and to permit server address changes without interfering with client services.
The problem with CNAME records is that they are prohibited at the zone apex by the governing dns rfc standards. That is, www.example.com is permissible as a CNAME record, but example.com is prohibited as a CNAME record. Therefore, a site using CNAME based services exclusively cannot have a site at the example.com name.
The lack of both the dns record and a site attached to the zone apex if the visitor types in example.com rather than www.example.com is a loss of visitor traffic.
The solution is to respond to requests to example.com with a http redirect to www.example.com using a server outside of the service which restricts the use of the zone apex name.
The edgedirector http redirection service is deployed at multiple geodns enabled servers. Clients using this service can setup http redirects from any name in their domains to any other name in their domains.
A client with a web site at www.example.com which is served by a service limited to CNAME records would setup a http redirect from example.com at the edgedirector redirection server to www.example.com on the site provider servers.
The redirects are transparent to visitors and combine all commonly used redirection techniques to ensure that visitors are not left stranded with a site not found message on their screen. Visitors requesting example.com will always arrive at www.example.com through these mechanisms. Using the http redirection service will instantly stop traffic leakage due to site naming restrictions.
The edgedirector http redirection service may also be used to push traffic from one domain to another in situations such as company rebranding, referral networks and defunct names.
Affiliate marketers and traffic aggregators can use chained redirects crossing domains as a means of referral masking to protect the source of their user traffic.
The http redirection facility is a metered pay-per-use facility.