Shared Domain

Sharing domains can be an effective method of fully utilising the resources of a server and also ensuring redundancy is available in case of faults or server load balance issues. Domain names and IP’s can have a relationship different to the standard one hostname to one IP most would expect. There can be multiple domain names to a single IP address to allow for a single server to host multiple sites as well as multiple IP addresses to a single domain to provide redundancies in cause of faults and to balance the loads placed on certain servers.

Many users and small companies use shared web hosting servers that use the same domain. Domain sharing can be an effective method to ensure full use of server resources. There may be several domain names under the same IP address and thus allow a server to host more than one web, it is also possible to find several IP addresses pointing to a single domain to provide redundancies in the cause of the failures.

If we want to access a website that is hosted on the same server as another website and share the same IP address, the DNS would resolve the domain name, send the response to the corresponding device and the device browser will request the corresponding server including the name of the host, so the server will be able to deliver the correct website.

In case of failures, large web hosting companies may have several web servers that share the same domain, to ensure their users access. This would imply having a single domain name resolution for one of several IP addresses. The one who would choose the access to the server would be DNS who resolved the IP, but there are resolution methods such as Time to Live DNS that will test an IP address and then, if a failure occurs, try another available one, thus avoiding the overload of the servers.