After all, what is a DNS server? Understand here!
Do you know what a DNS server is and what it has to do with your connection? Acronym for Domain Name System, the solution was invented to allow the growth of networks based on TCP/IP. Still, in the early 1980s, the implementation of technology brought significant changes, enabling the replication and distribution of information between computers.
With this in mind, this content presents the main points about the DNS server: what it is, how it came about, what it is for, what the main types are, and why this technology is important for the user. Furthermore, the article shows which DNS servers are most popular, how authoritative DNS and recursive DNS differ, and how and when to configure domain DNS.
In the end, you also understand how the DNS server directs traffic to the web application, an action that is subject to malicious attacks, such as cache poisoning (DNS Poisoning), server hijacking (DNS Hijacking), and flooding SYN (Syn Flood). Therefore, it is essential to have a good DNS service in your projects.
Continue reading and learn more about the topic!
After all, what is a DNS server?
Clearly and objectively, a DNS server is a computer that contains a database with Internet Protocol (IP) or Internet communication protocol addresses and their respective associated domains. It’s worth mentioning that there are several of them out there: they run specific software and communicate with each other based on special protocols.
In practical terms, servers make the connection between a domain and an IP number, which is nothing more than the identification of the server to which the domain is pointed.
To make things even easier, a DNS server is the system that translates “site.com.br” into an IP address, for example, 188.8.131.52. This occurs when the domain is typed into browsers.
How did the DNS server come about?
To talk about DNS we have to go back to the origins of the modern Internet. As we know, the World Wide Web is structured through IP addresses. See now how these servers came about and how they developed!
All points of contact on the Internet have a unique IP address: hosting servers, websites, access devices, routers, etc. The origin of the TCP/IP protocol dates back to the prehistory of the World Wide Web, with ARPANET, which already exchanged data packets using this protocol.
Adding new computers
As there were few computers connected, the structure was very simplified, as the network had a single text file, which contained a table containing the respective IPs.
As they added new computers to this network, the engineers realized that it was a lot of work to maintain and update this file, and it was not intuitive at all. It was in this scenario, with the need to automate the management and creation of new IP addresses, that DNS emerged.
DNS was invented in the early 1980s to make the Internet easier to scale, enabling the expansion of the computer network via the TCP/IP protocol.
The most significant change was that information was no longer concentrated on just one computer and began to be replicated on other machines, which were used for the same purpose, but which were far from each other. This is how the distributed system was born.
An IP address is structured by a sequence of numbers and dots. For example, Google’s IP is 184.108.40.206 — if you copy this string and paste it into your browser, you will go to the search engine’s main page.
What are the components of a DNS server?
Now that you know how the DNS server came about, it is important to know what the components of this important technology are.
The DNS system is mainly composed of these three components:
- authoritative servers, also known as authority servers;
- recursive servers;
- and customers, sometimes called resolvers, due to the specificity of each demand.
In short, authoritative servers have the authority to provide information about a domain, that is, they are configured when assigning DNSs to a specific domain.
In turn, recursive servers are responsible for searching for the IP addresses of a server to which the user requests access.
Customers install programs on computers with TCP/IP software, which can be confused by anyone who connects to the internet.
What is the role of a DNS server?
Having seen what a DNS server is, let’s now look at its role. We just mentioned translating friendly names into IP addresses, which, in short, is its initial purpose. See below the main functions of these servers!
There is no need to memorize huge sequences of numbers, just the domain. And this is precisely the purpose of DNS, allowing you to find web content by its name.
Without this system, you would have to record the IPs and type them into the browser. Imagine having to type “220.127.116.11” to access Google and “18.104.22.168” for Facebook.
To put it into context, we can say that the DNS performs a function very similar to a telephone directory. However, instead of associating people/companies with their phones, it matches names with their IP addresses.
When requesting a domain, the request is forwarded to the server responsible for servicing the domain, which will direct it to another server that hosts the website.
How important is the DNS server to the network?
Regarding the importance of a DNS server for the network, the point to highlight is that, when correctly adjusted, it favors user navigation. Understand that it is he who “starts the work” for a good experience, reducing the waiting time involved in translating domains to their corresponding IPs.
When not well configured, the resolution time to receive the requested data on the network will be somewhat longer, meaning that requesters will have to wait a little longer.
We can say that DNS is a silent gear that benefits a good connection. With pages becoming more and more robust, all mechanisms that provide connection must be in full operation.
How does this type of server work?
Regarding the functioning of DNS servers, the point to highlight is the search and redirection processes.
The first one has to do with searching for the IP corresponding to the domain entered in the browser. The second refers to redirecting the IP found to the server on which the requested website is hosted.
In this context, it is interesting that you know that there are 13 main DNS servers around the world, called “root”. Without them, browsing the Internet the way we do would not be possible.
What is the responsibility of a DNS server?
First of all, it is necessary to understand that DNS is a hierarchical naming system that is based on data, distributing this information across computers, services, devices, and resources connected to the internet or a private network. Therefore, the DNS server’s responsibility corresponds to translating names into IP addresses according to the TCP/IP protocol in the corresponding networks.
Why is DNS server distribution hierarchical?
In addition to the root servers, which we just mentioned, there are the “top-level domain” and “authoritative” types. This distribution is hierarchical, working as follows:
- the “root” type is at the top of the hierarchy, with the function of indicating the top-level domain server consistent with the user’s request;
- the type “top-level domain” ( Top Domain Level /TDL) comes right below, being represented by servers that house websites with the ending .gov, .edu, .org, .net, .com, .br, .uk, .au, etc.;
- the “authoritative” type is the last of them. As the name suggests, this type of DNS server is established for its purposes (universities and large organizations that want a single system for their records).
It is important to make it clear that the root servers know all the addresses of all other “top-level domain” DNS servers. That’s why they indicate them according to the user’s request, making the search easier for browsers.
This “tree” of hierarchical and distributed branches was created to prevent a failure in any of the servers from making network connections unfeasible.
Despite a certain complexity, the functioning of DNS servers is based on what we said: finding the IPs requested in browsers to redirect them to convergent hosting servers. That’s what you need to know.
What is the function of the configuration panel on a DNS server?
The configuration panel is a process that is generally carried out within the hosting company’s configuration panel.
It is always important to highlight that DNS settings allow you to use your domain as the basis for several services, on different servers. You can have your website on the main hosting, your e-commerce on a specialized platform, your email on a professional email server, a games page on a specific platform, etc.
In addition to the configuration panel, some records can be made when configuring the DNS server.
What records are allowed by the DNS server?
When we talk about DNS, the focus is always on showing the records that point to the hosting servers.
However, a domain can carry several values, which have specific purposes. If you have a domain and want to create a subdomain from it, you will have to add a CNAME record in the DNS configuration area.
This is because the DNS server is divided into different types, from CNAME records to DNAME records, through LOC, AFSDB, A, AAAA, SOA, NAPTR, MX, NS, and TXT records.
To help you apply the solutions strategically in your company, and discover what the “alphabet soup” means, we have listed the characteristics of DNS server records. Check out!
NS, or Name Server, type records are those related to the company that has control over the definitions of the domain in question. The website administrator, when editing the DNS of his domain, must include an NS record that will point the domain to the company that hosts the website. The NS registry usually has a similar structure to: ns1.empresa.com.
Type A Records
Type A records are those that always point to an IPv4-type IP address. These records can be used when you want to point your subdomain to a specific server. To redirect to the IPv6 address standard, you must use the AAAA record.
AAAA type records
It is true that type AAAA records perform the same functions as type A. But the difference with this solution, which is very functional on a DNS server, is the mapping for the IPv6 address standard, according to the current protocol that makes it possible to send and receive information via the internet.
LOC records specify information about the location of computers around the world. Therefore, the solution is ideal for checking the latitude, longitude, and height of a machine with internet access or a private network.
CNAME records point to and indicate the chosen subdomain. It is common for CNAME records to be previously configured in your hosting account with the value “www”. Yes, although we are used to “www” indicating a company’s main website when you type “www.empresa.com.br”, you are typing a subdomain.
The CNAME record can be used to create any type of subdomain you want. You can register the CNAME “blog”, to create the address “blog.empresa.com.br”, or register “store”, so that your e-commerce address is “loja.empresa.com.br”. The options are endless and you can use your creativity to create good subdomains to personalize your page.
AFSDB records perform domain mapping on database servers. The role is essential for strategic IT actions to be put into practice, ensuring the security and effectiveness of the technological solution.
Unlike CNAME, which maps only a single namespace, DNAME records offer the possibility of mapping DNS names in other domains. Therefore, the solution is interesting for customers who need a domain name on a database server.
NAPTR records are common in internet telephony applications, where they work by mapping servers and user addresses in the Session Initiation Protocol (SIP). In this sense, the combination of NAPTR records with service records (SRV) makes it possible to chain multiple records together, rewriting complex rules when producing new domain labels.
The MX record is the one that must always point to the server that provides your email service linked to your domain. This way, you can have your website hosted on one server and your email on another.
A TXT record is used for you to enter additional information about the domain in question. You can, for example, increase the security of emails sent from the chosen domain.
The SOA record — Start Of Authority — is the place where information about the authority responsible for the domain and other relevant information will be indicated, such as, for example, the date of the last update of the domain.
Should I opt for a free or paid DNS server?
As we saw throughout the post, DNS serves to translate an intuitive domain name that you typed into a browser into the IP address that will lead to the desired website. The better the DNS server, the better the user experience when accessing your website.
As we have seen, it is your ISP that assigns DNS servers each time you connect to the Internet. However, it will not always make the best choice of DNS server available and this can cause slowdowns before websites start to load.
If your server goes down, likely, you will not be able to access any website. In this scenario, you must carefully evaluate the chosen server, so that you do not have to change while the site is up and running, losing traffic and visits.
The differences between a free DNS and a paid one start from the obvious, one has no financial costs and the other does. Both options present the basic resources necessary for you to register domains and subdomains.
But paid DNS offers extra features like advanced security, performance functionality, customer support, and other extra customization options. Always focus on cost-benefit, and not just on price, after all, you will be investing.
How to act when DNS is not responding?
We have just discovered, in the topic above, how a DNS works, but we also need to understand what happens when it does not respond and how to resolve this issue.
In some situations, it simply stops working; in others, it may be a problem with the web, which ends up being reflected in the servers, and there are cases where the router is configured incorrectly. In this topic, we will learn how to diagnose and resolve this issue on different operating systems. Follow along.
Fixing errors in Windows
Let’s understand what are the main causes that make a server not respond in Windows 10, 8, and 7. Some of the most common are:
- internal problem with the router or network adapter;
- damage to the DNS service present on the device;
- blocking antivirus or firewall for internet access;
- server can be on the website host.
We will know the main causes, but how to solve this problem in Windows? The first thing that should be done is to reboot the modem device. Turn off your computer and modem device and wait a few minutes. Then turn them back on and check if the problem is resolved. This is the most basic resolution.
If it doesn’t work, you can try to resolve the error using the command prompt. See the step by step.
- start the command prompt by pressing the Windows + R keys and then typing CMD;
- then run the commands below one by one:
- Ipconfig / release;
- IPconfig / all;
- Ipconfig / flushdns;
- Ipconfig / renew;
- Netsh int ip set dns;
- Reset winsock netsh.
This sequence will flush DNS and fix errors, but for it to complete, you must restart your device and check your internet connection.
Changing DNS Addresses in Windows
To begin, right-click on the network icon and choose the “Open Sharing Network” option;
- then click on “Change adapter settings”, click on your network connection with the right mouse button, and then on priorities;
- then, choose the option “Internet Protocol Version 4 (TCP / IPv4);
- Now, you must add the DNS servers below:
- in the “Preferred DNS Server” area, enter 22.214.171.124;
- in the “Alternative DNS Server” area, enter: 126.96.36.199
- then close any open dialog boxes and check
Follow the steps below to be able to set your physical address as a network address using Windows:
- open command prompt;
- type the command ipconfig / all and press the Enter key;
- you will receive the connection details of the computer system and must note the physical address;
- then press the Windows + R keys;
- in the dialog box, type the command ncp.cpl and press Enter;
- right-click on the network option that is working and then click on “Priorities”;
- then click the “Configure” button and the “Advanced” tab;
- Now, click on the “Network Address” option;
- in the “Value” field, enter the physical address you wrote down, click “OK” and then “exit”.
Now check your connection and whether the pages are working normally. Otherwise, follow the steps below to configure your firewall.
Finding out what’s preventing my connection
Few people know, but firewalls and antiviruses can be configured in a way that prevents your connection. Therefore, it is important that, if the previous solutions do not work, you check your settings.
The best way to know if the problem is your antivirus is to disable it and check if the internet is working; If that doesn’t help, you’ll need to look into the settings specifications for your software brand.
Fixing errors on macOS
Now that we have almost a tutorial for you to check DNS problems on Windows, which is the most popular operating system in Brazil, we will explain how to resolve this issue practically on other systems, starting with Apple’s macOS. Check out:
- first, click on the Apple icon, which represents the Apple Menu;
- then click on “System Preferences” and then on “Network”;
- check your active connection and click on it;
- Afterward, you must click on the “Advanced” button and access the “DNS” tab;
- delete the IP addresses in the left table and then click the “+” button to add new ones;
- Now, you must enter the new primary and secondary DNS addresses (we will explain this in the last topic) and check the changes.
Fixing errors on iOS
Still correcting errors on Apple devices, let’s go step by step to resolve DNS unresponsive problems on the iPhone operating system, iOS. Check out:
- the first step is to open the Settings app;
- then tap “Wi-Fi”;
- when changing the screen, you must tap the “i” icon next to the network you want to change;
- tap “Configure DNS”;
- then, go to the “Manual” option;
- click on “Add Server” and enter the primary and secondary DNS addresses;
- to remove DNS addresses already registered, simply tap the red icon next to each one;
- To finish, tap “Save”.
Fixing DNS on Android
Now, let’s see how to modify DNS on the most popular smartphone operating system in the world, Android. The step-by-step is simple, and even laypeople will be able to do it. Follow:
- go to the settings icon and then to connections;
- tap “Wi-Fi”;
- Now, click on the Wi-Fi network you want to configure;
- tap “Advanced”;
- then tap “IP Settings” and then “Static”;
- Now, it’s time to define DNS 1 and DNS 2, adding the primary and secondary DNS addresses;
- So, just save the settings.
If, after the configurations, nothing is resolved, it is very likely that the problem is on your network. In this scenario, the ideal is for you to contact your provider to find a suitable solution.
What are the most popular DNS servers?
Before we finish this article on what a DNS server is, we will show you the most popular ones (which are also among the best). Essentially, they are:
Google Public DNS
Google Public DNS is a very simple service, just offering the translation of domains to their IPs. To use it, the computer or router must contain the following addresses:
- 188.8.131.52 (primary server);
- 184.108.40.206 (secondary server).
Another well-known is OpenDNS, which offers additional features such as parental protection systems and protection against fake websites. Their addresses are:
- 220.127.116.11 (primary server);
- 18.104.22.168 (secondary server).
In addition to these, Level 3, Comodo Secure DNS, Norton ConnectSafe, and DNS. Watch servers are also among the best.
The DNS server is one of the main agents that allows the structuring of the internet as we know it today. Understanding its structure and configurations allows us to make our websites and web applications increasingly optimized.
What are the differences between authoritative DNS and recursive DNS?
At this point, you already know what the different types of DNS servers are. But the question that remains is about the characteristics of authoritative and recursive DNS, right? Check out!
The authoritative DNS is responsible for identifying responses to recursive servers with IP address information and has the final authority over the domain. Authoritative DNS has an update mechanism used by developers to manage public DNS names.
Therefore, it converts domain names into IP addresses so that computer systems can communicate and respond to DNS queries.
Clients do not typically query authoritative DNS directly. In reality, they seek connection to another resolver or recursive DNS, which acts as an intermediary to obtain data. This type of DNS forwards the query to authoritative DNS servers to identify the information. If it has the reference cached, it can respond with IP data.
How to configure domain DNS?
To configure the domain DNS it is necessary to take some essential steps. Hire a hosting system or host to start the website, as it will store the information on the server. Register a domain through companies that offer this type of service. Below, check out a step-by-step guide to carry out the configuration!
If the hosting system is different from the company providing the registry, configure it to connect the domain to the DNS server. The connection is a type of registration of the name in a list of existing names.
The address will go through the propagation process, which takes between 24 and 72 hours to make the website live. Propagation replicates the new domain to servers around the world so that the address can be identified in any country using the World Wide Web.
Find the “change DNS servers” option in the dashboard. In the “editing data” field, there are two other fields for “slave 1” and “master”. Paste the nameservers indicated by the hosting provider into them, save the data, and wait for propagation. This is a basic step that applies to the options available on the market.
When is it necessary to change the DNS of a domain?
It is important to change a domain’s DNS whenever it is first registered. In this case, you need to modify the values to show them to the server that will host the website. If registration is done with the same hosting company, the DNS may be pre-configured to indicate your server.
You will need to change the domain’s DNS if you decide to migrate hosting, as each service has a different IP address. When migrating the server site, it is essential to modify the domain values to direct users to the new server. It is also crucial to make the change when you notice an error on the page.
How to change the DNS of a domain?
As you can see, there will come a time when you will need to modify your website’s domain values to point to a new hosting server. Next, we will show you how you can make this change!
Check where the domain is registered
Identify the company with which your domain was registered and analyze the area it makes available for editing the domains registered by it. If you used Registro.br, access the control panel, select your domain, and click on “Change DNS Servers”.
Locate the hosting server name servers
Whenever a hosting service is contracted, the company provides the hosting name servers. With these values, it is possible to connect the purchased domain to the host. Have this information at hand and return to the control panel to perform the next step.
Change the DNS of the domain with the server’s name server
After obtaining the name server from the hosting server, enter the values in the specific area that allows you to edit your domain. Then save these changes. But understand that the domain needs to be configured before changing the DNS at the registration location. Otherwise, the change will not be carried out by the system.
How does the DNS server direct traffic to the web application?
The user opens a browser, types an address in the address bar and presses Enter. This request is sent to the DNS resolver that is managed by the Internet service provider. It forwards the request it passes to the DNS root name service.
The ISP’s DNS resolver, in turn, forwards the request to one of the domain’s TLD servers. This server responds with the names of the servers that are associated with the domain. From this, the ISP’s DNS resolver obtains the IP address the user needs and returns the value to the browser.
What are the types of attacks on DNS servers?
Initially, it is important to understand that attacks on DNS servers aim to misdirect the destination requested by the user.
This explains why attackers use techniques such as cache poisoning (DNS Poisoning), server hijacking (DNS Hijacking), SYN flooding (Syn Flood), DNS tunneling (DNS Tunneling), and ghost domain, transforming the functioning of DNS servers. Get to know each of these attacks!
Cache Poisoning (DNS Poisoning)
In computer networks, cache poisoning (DNS Poisoning) is a technique by which an attacker sends spoofed Address Resolution Protocol (ARP) messages to a local network. The action occurs when a browser asks the server for an IP number for a domain, but the server sends the wrong number, maliciously redirecting the user to another page.
Server Hijacking (DNS Hijacking)
Server hijacking (DNS Hijacking) depends on replacing the TCP/IP configuration, which redirects traffic to an unauthorized server, taking into account the attacker’s control. Also called redirection, the attack is characterized by altering DNS servers, modifying the name resolution query on the server, and directing users to malicious websites.
SYN Flood (Syn Flood)
In the case of SYN flooding, the idea is to cause a direct overload on the transport layer, which also affects the application layer of the machines. Thus, the attacker sends a sequence of SYN requests to the system and, upon receiving the client’s request, the server exchanges the messages. As the protocol is incomplete, the last message does not reach the user, being replaced by the false SYN packet.
DNS Tunneling (DNS Tunneling)
With DNS tunneling, the technique uses the DNS server to bypass the firewall. The objective of this attack is to collect internal data from a network, which explains why the attacker can extract information or insert new code into existing malware during the action. DNS Tunneling is also used to bypass captive portals, avoiding payment for telephone services and internet access.
Finally, the ghost domain configures the DNS server, forcing it to resolve specific demands. But, as the solutions do not respond or take time to respond to the user’s request, the DNS server starts to consume more resources while waiting for responses. The result is performance degradation or complete failure of pending queries.
Why is it important to have a DNS service in projects?
The importance of having an agile and reliable DNS server is that it ensures the website loads quickly and correctly. If there is a delay in responding to a request, there is a direct impact on the website’s ranking system. For this reason, its configuration provides greater agility in obtaining data.
On the other hand, be aware that certain DNS tools are very useful for carrying out these processes. One of them is known as DNS Checker. This is a checker that allows analyses to be carried out on the extent to which the domain has spread throughout the world.
It works for those users who have recently changed hosting providers or created a new website. The Into DNS tool is excellent for checking DNS records for a certain domain, including those of competitors. With it, the user also discovers which email or storage services are in use.
To conclude, nothing better than helping you choose the ideal DNS server for your connection. Here, the tip is quick: use DNS Benchmark, a little program for Windows whose purpose is to present the best option for your region. We hope you understand what a DNS server is.
In this content, you understand what it is, how it came about, what it is for, what are the main DNS server records, and the technology that holds the internet communication protocol. However, to guarantee the security of the IT system, it is ideal to have a DNS service in your company’s projects, avoiding attacks and instability on the platforms.