What Is DNS? - DNS Resolution and Caching

Here are the solutions for DNS Resolution and Caching?

DNS stands for Domain Name System and is the method by which the Internet works. dns It is a method of converting domain names (such as Google.com) to an IP address dns, then locate the Web server where the website is hosted and display the page of the person dns requesting the information. This is done through a series dns of messages transmitted between providers and services Internet name servers dns.

How does the DNS?

The whole system starts when a domain name is written dns in the taskbar (for this example we will use Google.com ). Once this is done your first computer dns checks its cache to see if they have a record of the IP address of this page and, for this example dns we will assume that you have never visited before Google.com.

If there is no record in the local cache of your computer dns will ask your ISP (Internet Service Provider), if you can find the IP address of the server containing Google.com. Your ISP then contact a "root" server (owned by the ICANN Board of the Internet) that will return an answer where to look for.com domain names. The root dns server is known as a recursive name server since the ISP account where to look next and does not offer a definitive dns answer.

Once the ISP know where dns to look for.com domain names will ask this name server to find information on "Google.com" (note that we are now searching the entire area, not just the extension). This dns recursive name server checks the records and say this is the IP address of the ISP for that domain dns running on a server called "authority" and give its location in the ISP.

The ISP then ask the server name "authority" for the IP address of Google.com (s authoritative, since it is the end of the line and has the dns answer we want). This IP address will be returned by the access provider equipment. Your computer will connect dns through your ISP's IP address directly to the maintenance of Google.com web server and display the page for you.

This whole process is called "DNS resolution" or a "DNS lookup" and is the key to the functioning of the modern Internet, and we can remember much better than the IP addresses of domain names. To accelerate this process every step of caches was dns established that allows the ISP to avoid having to go to each recursive name server. This is both a dns blessing and a curse, as it greatly accelerates the time to load pages, but it means that any changes to the web configuration and (as IP, which is a site) sites can take up to 48 hours to be seen by all as caches still point to the old location and load the old page!

I hope this has given you a little help in understanding what DNS and why dns sometimes the Internet is not as immediate as we would like it to be!