Tag: DNS resolution

What is the purpose of DNS cache?What is the purpose of DNS cache?

In this post, you will discover the primary purpose of the DNS cache and how you can delete it. Let’s begin.

DNS cache – definition

The DNS cache is a type of temporary cache memory used by devices and DNS resolvers to store all previously used DNS records for the searched domain names. For example, the IP addresses of domain names and subdomains, data for their services, information about their email server, verification and authentication information, and so on are all contained in these records. Based on each DNS record’s TTL (Time to Live) value, the data will be saved in this DNS cache.

How does it work?

It works in a simple way. A DNS lookup is triggered whenever a user requests a domain name. Then the user’s device will initially look in the DNS cache built into its operating system (OS). It’s a database where distinct DNS records and their TTL values are stored. As previously stated, that TTL is established by the domain’s DNS administrator. The needed DNS entries can be found immediately there if the TTL hasn’t expired. The request will be fulfilled, and the domain will load extremely quickly. However, if the TTL has already passed, a new lookup will require additional time for the entire process to repeat.

This indicates that a DNS recursive server will accept the user’s request and request DNS records from other servers. First, it will query the root server, which will lead to the particular TLD server that should be searched, and then the recursive will be sent to the authoritative name server, which will finally supply DNS data (records).

The information will be transmitted to the user’s browser so that the domain can be loaded. Those data will be cached in the recursive server’s DNS cache, and the user’s device (computer, tablet, or mobile) will have access to them for as long as their TTLs allow.

Could you delete a DNS cache?

Yes, you can do it yourself. The clearing method varies depending on your operating system and browser, which may have its own DNS cache.

  • On Windows

So, first, find the Command Prompt and open it. Then type the following command: 

ipconfig /flushdns

Then you have to see a confirmation message. This is because the DNS has now been cleared.

  • On Linux

Launch the Terminal. Then run the following command:

sudo systemd-resolve –flush-caches

After that, type your sudo password and hit Enter. The DNS cache is deleted!

  • On macOS

First, open the Terminal. Then type the following command:

sudo killall -HUP mDNSResponder

After that, type your password and press Enter. Ready!

Okay, we see how to clear the DNS cache on different operating systems. Now, let’s see how to do it in different browsers:

  • Google Chrome/ Edge/ Opera

Chrome:/net-internals/#dns – copy this line. Then paste the line into your browser’s address bar. Enter your password. So now, on the page, look for “Host resolver cache” and then click “Clear host cache.” Ready!

  • Safari

In Safari, you can delete your cache by a different method type. First select “Advanced” from the “Preferences” menu. Next, look for “Show develop menu” in the toolbar there. Then find “Develop,” followed by “Empty Caches.” Ready!

Conclusion

In conclusion, we can agree that the DNS cache is a helpful tool for speeding up and streamlining the DNS resolution process. However, if necessary, you can delete it by following the steps above, depending on your operating system.

Anycast DNS – 3 Reasons why you should choose itAnycast DNS – 3 Reasons why you should choose it

Anycast DNS is a really useful service that can help your business. It makes surfing the web much faster and more efficient. So, let’s explore that a little more.

Different Routing methods

To send or receive data, you have a few alternatives. However, each of them has its own set of requirements implemented in various settings.

  • Anycast is comparable to Unicast in many ways. There is one significant difference, however: there are several hosts. As a result, the inquiry will be forwarded to the closest host. 
  • Unicast is a one-to-one communication system. This is the most fundamental technique in which all traffic is sent to a single site.
  • Broadcast is a term that most people are familiar with from television and radio. The data is carried from one point to all in this system.
  • Multicast is one-to-many as well, though not to everyone. The traffic is only of interest to a small group. So, type is helpful if there are no local nameservers.

You’ve already briefly met Аnycast DNS. But let’s explain it in more detail.

Anycast DNS – detailed explanation

Most DNS providers provide anycast DNS service as an optional feature. It is a helpful tool for traffic routing that allows websites to provide content rapidly. This is made feasible by the multiple nameservers that store a specific identical IP address.

Each of these servers is located in a different geographical area in order to be closer to potential users. As a result, DNS queries are answered much faster, and the user experience is enhanced. In addition, the closest and available server will respond to the user’s request. As a result, the Anycast DNS service reduces latency to virtually zero, and your clients will not have to wait long to access and explore your website.

Furthermore, even if the nearest server is unable to respond, such as when it is under maintenance, your website will remain accessible. DNS resolution is completed quickly due to selecting the fastest path.

Benefits from using it

As you can see, Anycast is a convenient service. So here are the three reasons why you should choose it if you are still considering implementing it for your business. 

  1. The first one is that it is simple to configure. It’s easy to set up because you need to configure it on one server. Additionally, similar changes can be made across the entire network.
  2. The second reason why you should choose it is the improved uptime. A server can fail, but the likelihood of a group of servers failing at the exact moment is extremely unlikely. As a result, your website will have improved uptime, and your users will be able to access it at any time. In addition, the response time is faster. When your servers respond quickly, the waiting time is significantly reduced. Few potential customers will abandon your website.
  3. And the last one is better security. DoS and DDoS attacks might use many ways, but the common thread is that they use large amounts of traffic as a weapon against flood victims. Typically, the technology used to prevent and guard against such attacks is complex and costly. Given that Anycast DNS is excellent for load-balancing, the anomalous traffic might be distributed over the network without causing an issue. Your security will be much stronger if you use this excellent strategy. Don’t undervalue the security of your website.

Conclusion

Anycast DNS, in general, is a method of keeping traffic local. You route it to the nearest instance, ensuring that your clients receive quick and dependable service. Furthermore, it is simple to set up and will boost your networking. So it is definitely worth a shot!

DNS resolution – Essential behind-the-scenes processDNS resolution – Essential behind-the-scenes process

DNS resolution – Definition

The DNS resolution is a fundamental process that resolves a domain name to its IP address (IPv4 or IPv6). Without it, the entire Internet would work in a completely different way. However, it occurs behind the scenes because regular users don’t even notice that it is happening. People are used to typing a simple domain name, and the desired website is loaded in their browser. However, the user’s DNS query is actually traveling through several separate servers until it receives a full answer. 

DNS resolution process explained

Regular users are used to connecting with their favorite websites in the blink of an eye. However, the entire DNS resolution process actually takes a long path. So, let’s’ explain a little bit more about the steps of this process, which begins with the user’s desire to visit a precise website for the very first time. 

  1. The user makes a DNS query by writing the domain name into its browser’s address bar. That way, the DNS lookup for the needed IP address begins.
  2. The recursive DNS server obtains the DNS query and checks in its own DNS cache memory. The required IP address could still be available there. In case it is not found there, the recursive DNS server proceeds to the following steps. 
  3. Тhe recursive DNS server proceeds and queries the Root server, which is on the top of the DNS hierarchy. The Root is able to provide information only for the location of the TLD (Top-Level Domain) server, such as .info, .net, .com, and so on.
  4. The DNS query is redirected to the TLD (Top-Level Domain) server responsible for the precise domain name. This server holds information about where is the needed name server for the domain.
  5. The recursive DNS server (DNS resolver) proceeds and requests information from the authoritative DNS server of the domain. This server carries the needed data (IP address) of the domain name, and it is the one capable of delivering an authoritative answer to the DNS recursive server.
  6. The recursive DNS server receives the information and contacts it back to the browser of the user. Additionally, it is going to store the IP address in its DNS cache memory to provide a quicker answer in the future.
  7. The user receives the IP address (IPv4 or IPv6), connects with the desired website, and caches it in the DNS cache.

So now you understand that the DNS resolution is an extensive process with several steps. Yet, at the same time, the user sees it as a few seconds.

Why is it important?

The DNS resolution process is crucial for humans. If it does not exist it would be a challenge for regular users to use the Internet and connect with their favorite websites. Back in the days when DNS (Domain Name System) did not exist, all IP addresses were saved in a single Host file. However, that was not practical anymore due to the fact that the devices wanting to connect to the Internet got a lot more.

Thanks to the development of DNS and the process of DNS resolution, we are easily accessing each website that we want by simply typing the domain name. We are not required to memorize complicated IP addresses.