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The additional details about the way that DNS works is very helpful and has cleared things up for me.

The additional details about the way that DNS works is very helpful and has cleared things up for me.

Yaa, for me too!! good question and a very clear answer.

Thank You very Much Choojin for The info. But can you explain me with the OSI Layers. Because i have a project that to explain how the packets route. I have to describe with the OSI layers.

Thank You very Much Choojin for The info. But can you explain me with the OSI Layers. Because i have a project that to explain how the packets route. I have to describe with the OSI layers.

Hi Prakashanandan, You need to do some of the work yourself. The explaination of how it works is quite detailed so how about you explain how you understand it with the OSI Layers and people here can help guide you ?

Also, this little information can also help. Humans like to use easily remembered names (FQDN), whereas digital machines such as computers like to use numbers (IP addresses). DNS is simply the go-between, allowing us to enter a name into a Web browser’s address bar or e-mail address instead of a cryptic number. For example, I want to go to www.footballnigeria.com . Let’s follow the steps of how my Web browser accomplishes that:

I type www.footballnigeria.com in the Web browser.

The Web browser then asks the resolver (a background client DNS application that resolves FQDNs to IP addresses) to convert www.footballnigeria.com into an IP address.

The resolver first checks the host’s file and the local cache to see if the FQDN/IP address combination is available. If it is, the resolver passes the IP address to my computer’s network protocols to set up a connection. If not, the resolver contacts the name server at my ISP, asking it for the IP address of www.footballnigeria.com
.


If the ISP’s name server has that information in its cache, it will immediately return the IP address to the resolver, which once again sets up a connection. One important term that we need to understand is recursive name server. It’s simply a name server such as my ISP’s that relies on other name servers for authoritative answers.


If not found, my ISP’s name server takes over looking for the www.footballnigeria.com name server by querying what are called authoritative name servers. To explain, the three components of the FQDN www.footballnigeria.com determine the order of the authoritative name servers queried. Com is the top level of this particular name, so the search starts there; the next level is footballnigeria., and finally www.




First, my ISP’s name server queries the root name server (authoritative for .com, .net, etc). The root name server returns the IP address for the appropriate .com name server to my ISP’s name server.


Next, my ISP’s name server queries the .com name server (authoritative for name servers in the .com domain) for the IP address of the footballnigeria.com name servers. The .com name server returns the appropriate IP addresses to my ISP’s name server.

Now my ISP’s name server queries footballnigeria.com name server for the IP address associated with www.footballnigeria.com
.

Finally, my ISP’s name server has the required IP address, sending it to the resolver application on my computer so it can establish a connection.

Once connected, the Web server will send the specified Web pages back for display on my Web browser.

That seems like a great deal of back and forth just to get the IP address of a Web site.
Thankfully, these transactions take only milliseconds due to several features incorporated in the DNS protocol.

Also, this little information can also help. Humans like to use easily remembered names (FQDN), whereas digital machines such as computers like to use numbers (IP addresses). DNS is simply the go-between, allowing us to enter a name into a Web browser’s address bar or e-mail address instead of a cryptic number. For example, I want to go to www.footballnigeria.com . Let’s follow the steps of how my Web browser accomplishes that:

I type www.footballnigeria.com in the Web browser.

The Web browser then asks the resolver (a background client DNS application that resolves FQDNs to IP addresses) to convert www.footballnigeria.com into an IP address.

The resolver first checks the host’s file and the local cache to see if the FQDN/IP address combination is available. If it is, the resolver passes the IP address to my computer’s network protocols to set up a connection. If not, the resolver contacts the name server at my ISP, asking it for the IP address of www.footballnigeria.com
.


If the ISP’s name server has that information in its cache, it will immediately return the IP address to the resolver, which once again sets up a connection. One important term that we need to understand is recursive name server. It’s simply a name server such as my ISP’s that relies on other name servers for authoritative answers.


If not found, my ISP’s name server takes over looking for the www.footballnigeria.com name server by querying what are called authoritative name servers. To explain, the three components of the FQDN www.footballnigeria.com determine the order of the authoritative name servers queried. Com is the top level of this particular name, so the search starts there; the next level is footballnigeria., and finally www.




First, my ISP’s name server queries the root name server (authoritative for .com, .net, etc). The root name server returns the IP address for the appropriate .com name server to my ISP’s name server.


Next, my ISP’s name server queries the .com name server (authoritative for name servers in the .com domain) for the IP address of the footballnigeria.com name servers. The .com name server returns the appropriate IP addresses to my ISP’s name server.

Now my ISP’s name server queries footballnigeria.com name server for the IP address associated with www.footballnigeria.com
.

Finally, my ISP’s name server has the required IP address, sending it to the resolver application on my computer so it can establish a connection.

Once connected, the Web server will send the specified Web pages back for display on my Web browser.

That seems like a great deal of back and forth just to get the IP address of a Web site.
Thankfully, these transactions take only milliseconds due to several features incorporated in the DNS protocol.