Tag: Domain Name System

DNS Network

What is TTL and why is it important?

In our article today, we will take a look at the TTL. So, if you want to learn more about its purpose and why it is so important, you are in the right place. 

TTL – What is its main purpose? 

The value that specifies the time period or the number of hops that a data packet is put up to be alive is called time-to-live (TTL). Either across the network or in cache memory. It will be terminated when this timer runs out or the data packet hits its hop limit. Data packets are not all the same; they differ in size and shape, but they all have a unique TTL. The amount of time data packets should decide the time needed to live in a device to perform their missions.

How does it operate?

Massive volumes of packets will be routed around routers if they are not regulated. To get around this, each data packet must have an expiration date or a restriction. This makes it easier to track their progress and figure out how long they’ve been there. Packets also move through network points to get to their destination. As a result, a TTL value is included in each data packet. Only if time or hops are available, do routers receive the packet and forward it to the next network point. If the TTL indicates that no more hops/time is available, routers will stop transferring it.

On the other hand, routers send an ICMP (Internet Control Message Protocol) message. It reports IP errors and points to the packet’s source IP address.

Why is TTL important?

TTL is a critical method for controlling existing data packets and network traffic. Every day, networks get larger and larger. As a result, the volume of data packets passing through them is enormous. Without a means to govern them (expiration date), millions of old packets that served their purpose many years ago may still be floating around, causing confusion.

Time-to-live is an essential tool for determining if data is still valid in situations such as networking and device cache memory, as we previously discussed. Data that has been determined to be no longer useful can be discarded.

TTL also allows you to obtain information about packets, such as the amount of time they spent traveling and the whole route they took. This is critical information in terms of security!

TTL in DNS

TTL (time-to-live) in DNS (Domain Name System) indicates how long a DNS record, such as an A record or an ALIAS record, is valid (in seconds) and how long a nameserver (recursive or secondary DNS server) can store it in its cache memory. The DNS record will be removed when the TTL reaches 0.

The DNS client must ask the recursive DNS server again and wait for it to perform a fresh DNS query to obtain the record in the case of a recursive DNS server. Following that, it will be cached again based on the TTL.

To update its DNS records, a secondary DNS server must check with the primary DNS server again and complete a zone transfer. Otherwise, it will be unable to answer to domain-related questions.

Conclusion

To summarize, the TTL value is a critical component that determines how long data is valid. It will indicate whether the information is current or needs to be updated soon. It facilitates data updating.

DNS Network

The Ultimate Guide to DNS Propagation

What does DNS propagation mean?

DNS propagation is a process that includes updating and spreading the new changes and adjustments you create in your Domain Name System (DNS). They have to be distributed across the entire network. 

Managing your online business or administrating a network involves constant changes on the DNS. Some of the possible scenarios are when you have to add a new DNS record, delete or change some other DNS records, also replace IP addresses. Maybe you desire to make some adjustments on the TTL (time-to-live) values, redirect your visitors to a specific subdomain, or add an SSL certificate. These are only for illustration of how many different modifications of your DNS could appear. 

Actually, no matter what changes you desire to make, all of them are going to be stored on your authoritative DNS server. However, the network has many more DNS servers, like recursive DNS servers, positioned in different locations globally. Each one of these servers has to receive the updated data because if that doesn’t happen, they are going to have some difficulties operating properly. All of those DNS servers have a fundamental part of the DNS resolution process.

How does the DNS propagation work?

For several situations, DNS changes are required. Typical cases are when you desire to make some renovation to your website or when you migrate to a new DNS hosting provider. Different circumstances that can need it are redirecting from the primary domain to subdomains or implementing services, such as FTP and email. All of these circumstances incorporate activities, such as creating, editing, or removing DNS records

The administrator is going to make these corrections directly on the authoritative DNS server. Once the modifications are ready and saved inside it, it is time for the DNS propagation process to happen. That requires every DNS server on the network to obtain a copy with the latest DNS records. 

The DNS propagation process is rolling, although that doesn’t mean that it occurs simultaneously for all servers. 

How to check it?

Here you have three options to make a check on the DNS propagation. Decide depending on your operating system (OS).

For Linux and macOS users, here you have the Dig command.

First, open your Terminal, and next write: 

dig domainname.com 

It will trigger a lookup for an A or AAAA record. As a result, you are going to view the IP addresses of your website. If they have changed, DNS propagation is completed. If they haven’t, it will require a little more time.

*Replace with your domain name and TLD instead of the ones in the example.

For Windows 10 users, here you have the Nslookup command.

Open the Command Prompt, and then type: 

nslookup domainname.com

Once again, the lookup result is going to show out if your website’s IP addresses have changed or not.

*Replace with your domain name and TLD instead of the ones in the example.

Online checkers of DNS propagation.

You could use online tools for making DNS lookups to review data associated with your domain name. In addition, you can examine if the DNS modifications you created have been updated. 

DNS

DNS – a key piece of the Internet

DNS is one of the most important and essential pieces when it comes to the Internet. Without it, it will be very hard for humans to search, connect, and explore different websites. So, let’s explain a little bit more about it!

What is DNS?

Thanks to the Domain Name System (DNS), we are able to use the Internet as simple as it is in present days. However, it is an infrastructure with vast functionality. In its foundation is the database with all of the domain names and their corresponding IP addresses.

A long DNS process is triggered once a user types a domain name for connecting with it. So, the domain name has to be translated to a language that machines understand, which are the IP addresses. That is necessary because the machines communicate with one and another through numbers. Finally, when the IP address corresponding to the domain name is resolved, it can be delivered to the browser of the user. So, the user is able to reach and explore the website. In the time when DNS was not created yet, the user would have to type an IP address, for instance, 56.155.208.13. Instead, it is much easier to remember and type a domain name, for example, domain.com. Thus, DNS gave the opportunity for humans to use the Internet and successfully communicate with machines efficiently.

What is DNS used for?

  • It makes searching on the Internet flexible, easy, and simple.
  • The Domain resolution process is crucial.
  • Load balancing
  • DNS caching
  • Email servers and routing the messages
  • Additionally, for service’s routing
  • Verifying of services, servers, e-mails, and so on.

What is the structure of DNS?

The domain name space has a structure on several levels, and various DNS servers are positioned all around the world. On the top of the structure above all stands the root. The level below is for different top-level domains (TLDs). Under them are the secondary domains and subdomains.

Root level – This is the origin of the DNS. When the DNS resolution process is initiated, the search starts from this level. After that, it proceeds to one of the name servers for the domain’s TLD. It is represented with a dot “.” at the end of the domain name. However, everyday users don’t use it.

TLD level – The top-level domains are every extension you have probably seen, such as .com, .net, .co.uk, .info, and so on. Within the TLD name servers, you are going to receive the answer, for which name servers hold the information about the domain name you are seeking for.

Second level domain. This is the name of the website that you are searching for without the TLD extension. For instance, Google, from google.com.

Subdomain level – This is the subpart of the domain name. You can see it before the domain name. Moreover, it is divided by a dot (“.”). For instance, a blog subdomain is blog.google.com.

Why is it so important?

DNS is so essential because, without it, every action on the Internet is going to take a more prolonged time, and it is going to challenge us, humans, to memorize a bunch of information. The DNS assists communication on the Internet, plus it makes domain name queries seem so fast and straightforward. Thanks to the system, you can connect to nearly every website 24/7. 

Recommended article: The Ultimate Guide to DNS Propagation