Oscura Network Status

DNS - translating a URL into an IP address

08 December 2014

The Domain Name System translates a human friendly name, such as www.oscura.co.uk, to the IP address format used by computers.

The DNS or Domain Name System is used to translate a human friendly URL (uniform resource locator) such as www.oscura.co.uk to the IP address format used by computers - to (IP V4).

When a URL is entered into a web browser, the computer requests a connection to its local DNS servers. These are usually assigned automatically by the ISP (internet service provider) when the computer connects to the internet. The computer requests the IP address of the URL the user entered. If the DNS server has the information, it returns the IP and the web browser connects to the given IP to display the website. If the ISPs DNS server can't fulfil a request, it will forward it up the DNS hierarchy

DNS hierarchy

Taking the example of visiting www.oscura.co.uk. If the IP address for Oscura is not available from the local ISPs DNS servers, the DNS request will be forwarded to the root DNS servers. The root DNS servers have the master list of top level domains (like .com or .uk) and direct DNS requests to the server responsible for that top level domain. For instance in this case, the query for www.oscura.co.uk will get redirected to the UK domain servers. These servers are run by Nominet, the UK domain name registrar, all UK domains are registered with Nominet by Nominet members like Oscura. When each domain is registered with Nominet, it is assigned an authoritative name server, name servers which hold the records for the domain and allow subdomains and mail records to be attached to that domain. These are usually owned by the webhost, or by bigger companies. In this case, the UK DNS servers can see that the www.oscura.co.uk is registered on Oscura's DNS servers, so the request is sent onwards to Oscura, which will return the IP address needed to connect to oscura.co.uk to back to the computer that made the request, and the computer can view the webpage.

Oscura runs its own DNS servers for the sites we host, these servers are distributed over two locations for redundancy and maximum reliability. Oscura hosted sites receive free DNS support, including updating records and advice, to provide you with a hassle free service. We register European and Global Internet domain names and well as .uk domains as Nominet members.

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