Tag Archive For "What is DNS?"
In the articles of the "What is DNS?" series you will find answers to questions such as: why and how the domain name is defined, what is the difference between DNS servers and DNS records, why there is a propagation period after updating DNS information, and so on.
The time set in the DNS record TTL tells the DNS caching server for what period the record is considered up-to-date and can be stored in the cache. Typically, a TTL is set between 2 and 48 hours, and therefore, after changing the DNS information, a global refresh period of 2 to 48 hours is given.
Once the DNS resolver receives a DNS client request for the IP address of a domain, it initiates DNS check by sending a DNS request to one of the Root DNS servers.
In this first article in the What is DNS? we'll see what DNS is, and we'll find that the web browser itself can not know what a domain's IP address is, but will use the help of another application.