DNS ( Domain Name System ) is a system in charge of storing all domain data information on the network. With DNS, existing domains or hostnames will be translated and translated into IP addresses so that they can be accessed. DNS was discovered in 1983 by Paul Mackapetris. Before using DNS, domain mapping first uses the hosts.txt file.
The hosts.txt file has a drawback, namely when an IP address changes, the file must also change, so it is rather complicated. In contrast to DNS where changes are dynamic. So if there is a change in one host, then the others will follow, everything will be dynamic. For more details, see the explanation below.
Understanding DNS Servers?
DNS is a server that can serve requests to find out an IP address used by a domain. An easy example, when you want to access facebook.com, the DNS server will look for the IP address of Facebook so that your computer can access Facebook.
The use of this DNS server is usually set automatically on each computer and each internet service provider. But if not, you need to set the IP address first. If you use a router, then you can create your own DNS server. However, the search for IP addresses is still carried out by internet service providers.
From this little explanation, you will know the definition of DNS, right? So, the search for the IP address by DNS only needs to be done once. So when the IP address of a certain website is known, the computer will still save it or in other words cache the DNS so that when accessing the same website, there is no need to look up the IP address.
Functions of DNS Servers
The DNS server is a large database that functions to store all the IP addresses used in hostnames. This large database contains a lot of information about IP addresses so when you visit certain websites. For example, youtube.com, the DNS server will translate or translate it to the YouTube IP address.
So you can connect to YouTube and YouTube displays will appear in your search. In order to understand more about the function of the DNS server, we will assume it is like a telephone book on a mobile phone. For example, your phone number is 62857123xxxxx and you name it A in your contacts. Now, when you want to call that number, you just have to choose contact A. Later, the number in contact A will be contacted so that you can be connected to the owner of contact number A.
The phone number here is the same as the IP address and contact A as the hostname. So when you access contact A, the phone book will translate it into contact A’s phone number or when you access a website, the DNS server will translate it into the IP address of the website in question.
DNS management consists of three main components, namely the DNS resolver, the recursive DNS server, and the authoritative DNS server. A DNS resolver is a client that is known to be a user’s computer that is making DNS requests from a particular program. Meanwhile, the recursive DNS server is the party that provides answers to the resolver in the form of the requested DNS search results.
How DNS Servers Work
After a recursive search, a new authoritative DNS server appears as the responding party. The intended response can be a delegate or an answer to another DNS server. So it’s easy like this, the resolver program (web browser and mail client) will connect the user’s computer with the DNS server.
The DNS resolver will look for the host address in the hosts file. If it has been found, the data will be given to the client via a web browser so that the process is immediately complete. In addition to searching the hosts file, the DNS resolver also searches the cache data because the IP addresses that have been searched before will be stored in the DNS cache.
So when you visit the same site, the DNS resolver will look for it in the cache data and then provide the results to your web browser so that the process is immediately complete. DNS also looks up the address of the first DNS server when no data is found in the cache or hosts file. If you have used the method above, but the domain name is not found by the DNS server, then the next search is by looking for files on other server databases.
If not found, then the next search is by contacting another DNS server that is still in touch. So basically the DNS resolver will do a search first on the cache and hosts file, later if nothing is found then it will do a search on the DNS server database. If it is not found either, the search will move to the second, third, and so on DNS server until found.
Once found, the data will be immediately given to the client via a web browser view. Well, when you can’t access a website related to DNS, it’s most likely because DNS is unable to find the IP address of the website you are accessing.
DNS Types
Now we will continue to discuss the types of DNS because there are indeed several types of DNS. Immediately, following the type in question.
a) A record The first type is a record. This type maps the hostname to a 32-bit IP address or IP address which you may often recognize by the IPv4 code.
b) AAAA record For AAAA records map a hostname to a 128-bit IP address or you can call it IPv6.
c) MX record For an MX record, it is a type of DNS that maps a domain to a mail exchange server.
d) CNAME record There is also a CNAME record that will create another name or alias name for a domain.
e) NS Record For NS Record, domain mapping is done to a single list in the DNS Server.
Understanding what DNS is is inseparable from the types of DNS above. You can also find the DNS settings above in the domain control panel settings. Or it can also be managed from hosting if the domain name server and NS record have been set. On the computer, the DNS settings are in the network or network configuration.
For internet connections using WiFi that has a DHCP function, DNS settings are usually already through the router or AP. DNS can also be set to block certain sites. You can find it at certain internet providers such as Telkom’s DNS which only allows access to good sites or can be said to be positive internet, where you cannot access blocked sites.
The blocked site can actually be bypassed by manually setting the DNS with Open DNS, Google DNS, and so on. However, if the website block uses a redirect, transparent proxy, then the settings are also different, not only setting the DNS. You still have to use proxy IPs, web proxies, tunnels, VPNs, and so on.
Conclusion
To understand more, you can conclude that DNS acts like a heart for the body because of the importance of DNS in accessing the internet. When you surf in cyberspace using the internet, then immediately you use DNS. All applications or websites that are connected to the internet will first be translated by DNS so that you can access them. It needs something called DNS because computers do work with numbers and humans or users are more inclined to names that are easy to remember.