Question

There are many ways to take care of name resolution. Name one (that hasn't been named yet if possible) and discuss how it works and what commands are necessary to carry out the resolution. Is the method you chose still used in computing? If not, why not? If so, explain what makes it still useful.

Answer 1

A computer or a server identifying in network by IP Address but it is difficult to remember and we can remember name easily rather than IP address so use name resolution method. the different name resolutions are:

• LLMNR (link local multicast name resolution)
• NetBios (network basic input/output system)
• DNS (Domain Name System)

DNS (Domain Name System) - it's network service that translates names into IP Address that computers can recognize. In the world of networking, the computer doesn't go by names like humans do, they go by numbers, because that's how computers and other similar devices talk and identify with each other over a network, which is by using numbers such as IP addresses. Humans on other hand are accustomed to using names instead of numbers, whether is talking directly to another person or identifying a country, place, or thing, humans identify with names instead of numbers. so in order to bridge the communications gap between computers and humans and make the communications a lot easier network engineers developed DNS, and DNS stands for a domain name system and DNS resolves names to numbers to be more specific it resolves domain names to IP Addresses. so if you type in the web address in your web browser, DNS will resolve the name to a number because the only thing computers know are numbers. so for example, if you wanted to go to a certain website you would open up your web browser and type in a domain name of that website so for example let's use yahoo.com. now technically you really don't have to type to yahoo.com to retrieve the yahoo web page, you can just type in the IP Address instead if you already knew what the IP Address was, but since we are not accustomed to memorizing and dealing with numbers, especially when there are millions of websites on the internet, we can just type in the domain name instead and let DNS convert it to an IP Address for us so back to our example, when you typing yahoo.com your web browser the DNS server with search through its database to find a matching IP address for that domain name, and when it finds it will resolve that domain name to the IP Address of the yahoo web site, and once that is done then your computer is able to communicate with the yahoo web server and retrieve the webpage. so DNS basically works like a phone book. when you want to find a number, you don't look up the number first, you look up the name first then it will give you the number.

So, to break this down into further detail let's examine the steps that DNS takes, so when you type in yahoo.com in your web browser and if your web browser and if your web browser or operating system can't find the IP address in its own cache memory, it will send the query to the next level to that is called resolver server which is basically your ISP internet service provider, so when the resolver receives a query, it will check its own cache memory to find an IP address for yahoo.com, and if it can't find it will send the query to the next level which is the root server, the root servers are the top of the root of a DNS hierarchy. there are 13 sets of these root servers and they are strategically placed around the world and they are operated by 12 different organizations and each set of these root servers has their own unique IP Address. so when the root servers receive the query for the IP Address for yahoo.com, the root servers are not going to know what the IP Address is, but the root server does know where to send the resolver to help it find the IP Address. so the root server will direct the resolver to the TLD or top-level domain server for the .com domain. so the resolver will now ask the TLD server for the IP Address for yahoo.com. the top level domain server stores the address information for top-level domains, such as .com and .net, .org, and so on. this particular TLD server manages the .com domain which yahoo.com is a part of, so when a TLD server receives the query for the IP Address for yahoo.com, the TLD server is not going to know what the IP Address for yahoo.com. So the TLD will direct the resolver to the next and final level, which are the authoritative name servers. so once again the resolver will now ask the authoritative name server for the IP address for yahoo.com. the authoritative name server or servers are responsible for knowing everything about the domain which includes the IP Address. they are the final authority. so when the authoritative name server receives the query from the resolver, the name server will respond with the IP address for yahoo.com and finally, the resolver will tell your computer the IP address for yahoo.com and then your computer can now retrieve the yahoo web page. it's important to note that once the resolver receives the IP Address, it will store in its cache memory in case it receives another query for yahoo.com so it doesn't go through all those steps again.

• The Dig command is used to resolve the issue of DNS Server, the dig is stood for domain information Groper.
• The Nslookup command is used to perform DNS queries and receive as well domain IP Address or any specific DNS Records.