The Domain Name System, or DNS, was invented in the 1980s and has been improved over the decades. Still, the DNS stands in the way of flawless performance and flexibility of online transactions.
So, what is the problem?
Even the slightest change to a DNS record needs to be propagated, which may take anywhere from a few minutes to several days. This information synchronization periodically occurs between primary and secondary servers. That is what is called the refresh interval. Once a DNS record is altered, no one knows how long the propagation will take.
But even though this is still a significant inconvenience for Internet systems, it’s essential to understand how propagation works. Let’s examine DNS technology, propagation, common errors, and some ways you can speed up the refresh interval and the entire propagation process.
DNS: An Overview
Perhaps you’ve already heard a DNS is like an internet phonebook. But what does that mean exactly? Essentially, it is a system that converts hostnames or domain names into IP addresses. This conversion ensures the URL you search for loads into a web browser.
Therefore, a DNS is also like a translator, as humans can’t remember long sequences of numerical values, and machines don’t understand hostnames. The DNS is not something an average user has to worry about, as functions occur in the background. However, without it, looking for information online would be impossible.
Types of DNS Servers
Based on their structure, there are four types of DNS servers. All of them participate in the DNS resolution process. The servers are listed in the order a single query passes through them.
The recursive server is the first stop a query makes and comes from an application like a web browser. You can compare a recursive server or precursor to a librarian you ask to fetch you a particular book.
Furthermore, the recursive server is in charge of making additional queries that satisfy a specific request. Every recursive server either provides a direct answer or shows an error.
Root Name Server
The root server is in charge of initially translating the domain names into IP addresses. In the library analogy, the root name server directs you to different stacks of books. It typically points to more specific locations.
The Top Level Domain, or TLD server, takes the next step in searching for the unique IP address and is represented by the last part of an URL like “.com” or “.org.” Countless TLD servers around the world boost the speed of handling requests.
Authoritative Name Server
The next step your request goes through is the authoritative or non-recursive query. These servers host specific IP addresses for hostnames.
Upon receiving the request, the authoritative server will return with a specific DNS record that enables a web page to load. You’ll see an error message if the server doesn’t hold the corresponding record.
Most Common DNS Records
A DNS record is simply the information a single query asks from the server. However, the type of DNS record can vary depending on your application, client, and query. Each DNS record indicates how a query should be treated.
The “A” stands for “address” and represents the IP address of a single domain. However, the A records only relate to IPv4 addresses, but IPv6 addresses have AAAA records because their format is longer. It’s also important to point out that even though most websites have only one A record, some have several.
The same server or NS record points to the authoritative server for a specific domain. It’s common for domains to have more than one name server, meaning there is more than one NS record that directs queries in their direction.
This record allows network administrators to include text in DNS. They verify domain ownership and secure email transactions.
Canonical name records sometimes replace A records when an alias is involved. Essentially, they are used to re-try a query with two different domains but the same IP address.
What Is DNS Propagation?
All DNS changes occur on one authoritative name server to ensure the DNS servers have the same data simultaneously. These changes happen automatically within 24 and 72 hours. This update or refresh interval is called DNS propagation.
During this period, the Internet Service Provider (ISP) nodes update their caches with the DNS changes to your domain. While it might seem unusual to wait this long for any updates in the modern age, that’s the reality of the current DNS infrastructure.
However, some DNS vendors have created proprietary technologies that allow faster propagation time, and many developers focus solely on this problem.
Factors Affecting the Refresh Interval
The difference between a two-hour and three-day refresh interval is significant. So, what are some of the factors that affect this refresh rate?
Time to Live (TTL) Settings
This factor represents the time the DNS information “lives” on a remote server or the local machine. After this period, the system erases DNS information and prepares to receive new data. Shorter TTL means faster propagation.
For example, if you set the TLL for two hours and enter new information, the DNS server will deliver the old information for two hours before purging it.
Domain Name Registry
If you alter the authoritative name server for your domain, the propagation time will depend on where your website is in the DNS hierarchy. Websites with “.com” belong to the Top Level Domain (TLD) name server and will have a shorter refresh rate.
Internet Service Providers (ISPs)
ISPs can prolong the propagation time by ignoring the TTL settings. However, many routinely perform DNS lookup and cache DNS records to ensure faster website access.
There are a few other elements that impact the refresh rate, including:
- Amount of traffic between server and client
- Type of connection between your server and DNS server
- Distance between client and server
- The quality of the connection between the client and the server
DNS Propagation Errors and Troubleshooting
There are several errors DNS updates may run into, and most of them stem from the authoritative DNS servers. Usually, there’s a communication problem between the DNS server and the local server that handles user requests.
An error will occur if the IP address by the local server doesn’t exist in the DNS server’s records. Or the IP address was recently changed, and the DNS server records don’t yet reflect that change. Finally, the local server may be unreachable because it’s on the wrong network.
Another common issue is the DNS timeouts which are relatively common, though what causes them is not always clear. You can resolve DNS timeouts by re-configuring your router or modem or contacting your ISP. Sometimes, changing the default DNS settings on your device can fix a DNS timeout.
How to Speed Up DNS Propagation
One of the most efficient ways to speed up DNS propagation is to opt for a dynamic DNS provider. This is particularly important for e-commerce websites that take orders and need to see changes go “live” in record time.
Another great tip for preparing most changes and testing links, images, and other elements is to edit in a local host file.
What are the propagation times for major DNS providers?
Naturally, the biggest providers of DNS software try to offer the fastest propagation time. For example, Cloudflare’s DNS refresh interval is often just several minutes but can also take much longer. Google Public DNS tends to propagate within 48 hours, and the same interval applies to GoDaddy.
How do I find my DNS server?
In most cases, your DNS server is assigned by your ISP. The simplest way to see and find your DNS server is to use the Command Prompt tool on Windows or Terminal on macOS computers. If you’re uncomfortable using these tools, consider asking an IT expert for help.
It’s also vital to note that you’re not obligated to use the default DNS server and can change this setting. One of the easiest ways to do that is to connect your device to a public DNS server. One of the best solutions is Google Public DNS with the 126.96.36.199 IP address.
Is a DNS secure?
There’s a lot of discussion about the vulnerability of the DNS system. DNS leaks are not uncommon and can lead to the loss of sensitive information and extortion. DNS spoofing and re-direction are also known lines of attacks from cybercriminals.
Does DNS increase web performance?
Yes, DNS can increase web performance. Specifically, caching A records increases response time by storing previous answers to queries. But also you can cache DNS data in several ways.
For example, web browsers do this by default, which improves their performance. Furthermore, some operating systems have integrated DNS resolvers that automatically cache DNS data.
Who assigns IP addresses?
Every computer, smartphone, and tablet has a unique IP address, but you may wonder what entity assigns these numerical values. In the late ’90s, the U.S. government allocated this task to the Internet Corporation for Assigned Numbers and Names (ICANN). This non-profit organization has managed the IP address assigning process for over 25 years.
Making the Most Out of DNS Infrastructure
If you have a website, whether it’s a movie blog or an e-commerce business, understanding DNS refresh intervals is essential. Not seeing the changes you’ve made to your website instantly is somewhat frustrating, but the DNS infrastructure is not yet perfect.
Still, understanding the factors that affect the refresh rate can help you make decisions that will minimize the propagation time. Choosing a solid DNS provider is step one, but checking the DNS assigned by ISP and router re-configuring is important too.
Did you ever have to change a DNS provider to speed up refresh rates? Let us know in the comments section below.