In order to call up an internet page on the World Wide Web, you need the IP address of the server, on which the web presence is saved. Normally, only the domain name is visible and with good reason, too: numerical sequences, like 93.184.216.34, may form the basis of online communication, but they don’t tend to stick so well in one’s memory. So every IP address features a human-friendly name, known as a domain. For example:
IP address: 93.184.216.34
Domain: www.example.com
The translation of domain names into numerical addresses that computers can process is known as name resolution, an internet service handled by the Domain Name System (DNS).
The Domain Name System is a hierarchal naming system responsible for the management of domain name space. Its main task is to answer requests for name resolution. The DNS plays a similar role to a telephone directory, holding up-to-date contact information and publishing it on request. The system relies on a worldwide network of DNS servers that divide the name space into independently administered zones. This creates a decentralized control of domain information. Whenever a domain is registered, a new WHOIS entry is created in the existing registry. This comes in the form of a resource record in the DNS. So the database of a DNS server is a collection of all resource records in the zone of the domain name space for which the server is responsible.
When the domain name system was created in 1983, it solved an error-prone process for name resolution that was previously based on a localhost file. Even today, hosts.txt files can be found on Unix-based systems in the etc/ directory and on Windows computers under %SystemRoot%\system32\drivers\etc. The hosts.txt had to be maintained manually and updated regularly – which soon became too much effort in the rapidly growing world of the internet. Hosts.txt files are now only used in the fixed allocation of IP addresses on local networks. Additionally, they can be used to block web servers by automatically redirecting the corresponding addresses to the local host.
Whenever you enter a web address into the browser’s search bar in the form of a URL (Uniform Resource Locator), a request is made to the resolver. This is a special component of the operating system that stores previously sourced IP addresses in a local cache and delivers them to client applications upon request. Should the desired IP address not be in the resolver’s cache, then the request is forwarded to the responsible DNS. Typically, this is the DNS server of your internet provider. There, the request is checked against the DNA database and the corresponding IP address is found (if there is one). This is known as ‘forward lookup’, and allows your browser to locate the desired web server via the internet. Alternatively, IP addresses can translate in the opposite direction, finding the respective domain name (‘reverse lookup’). If a DNS server is unable to answer a query from its existing database, it can collect the corresponding information from another database, or forward the request on to a different DNS server. These are known as recursive or iterative queries.
The central management of domain information in the DNS is characterized by high reliability and flexibility. Don’t worry if the server address is changed at the IP level, because the unchanged domain in the database will simply be allocated to the new IP address.
A DNS server (also known as a name server) is a specialized server software that relies on a DNS database to answer requests on domain name space. DNS servers usually have dedicated host platforms, so both the host and the server are referred to under the same title of DNS server. In DNS operation, there is a distinction made between authoritative and non-authoritative DNS servers.
When network problems occur, users are often met with the error message ‘DNS server not responding’. In this case, the internet connection is lost and so websites can’t be accessed. For more information on causes and solutions to this, please refer to our article on what to do when a DNS server is unavailable.
‘DNS server not responding’ is a typical error response on Windows. Its presence indicates that some sort of problem is occurring with your internet connection. This phenomenon can be the result of many different causes. In addition to network problems, routers, Windows Firewall, and the web browser are also taken into account when troubleshooting.
Being able to access your home computer from another location is no longer a complicated matter thanks to remote connection. It is handy to be able to use your computer from the office and swap files. But IP addresses change often and this throws a spanner in the works. DynDNS (DDNS) services are the solution. In this article, we explain what these are and how you can access your computer via the...
You would like to access your home computer, but don’t know how? Does your home network with its constantly changing IP addresses jack up your monthly bill? Dynamic DNS services (DynDNS) can help you out. Find out which DynDNS providers are the best and what the advantages and disadvantages of each are in this overview.
The hosts file used to resolve website names so that certain IP addresses could be accessed. The method was largely replaced by the DNS (domain name system). However, the hosts file is still indispensable for local networks. In addition, certain rules can be set for websites e.g. to block them. We show you where you can find and edit the hosts file in your operating system.
