DNS (Domain Name System) is a system that translates domain names into IP addresses used by computers to locate servers on the internet. Think of this system like our phone numbers: we have an assigned phone number that allows people to reach us, as well as other phone numbers that allow us to call others that is then received on their wireless (or wired) devices.
What Exactly is Propagation and How Long Does it Take?
DNS propagation refers to the time it takes for your domain’s DNS information to be updated and propagated across the web after a change is made to the DNS settings. Propagation is the projected length of time it takes for your domain’s updated DNS information to be synchronized worldwide. This synchronization process typically takes between 24 to 48 hours to complete in full; during this period, not all visitors will be directed to your new name servers immediately. Some visitors may still reach your old website until propagation is completed.
Why Do Visitors Experience Delay?
The length of time it takes for visitors to be directed to your new name servers depends on several factors, including geographical location, internet service provider, and TTL. TTL (Time to Live) value specifies the duration of time that DNS records reside in cache before they expire.
Once propagation is complete, your site will appear on the new hosting server and be fully functional.
How to Determine When Propagation is Complete?
There is no definitive way to know when propagation is complete; however, several websites can track propagation progress, like DNS Checker, showing you when your website is likely to be visible once the entire process is completed.
DNS and Its Function in Keeping You Connected
DNS maps domain names to IP addresses, allowing you to connect to web servers. To connect to a website, your computer must first find the correct IP address on the server before sending a request to that server; this process applies to all internet services like email, chat, and games. DNS records work like a phone book, relating domain names with IP addresses to reach these services.
The Two Primary Functions of DNS Servers
DNS servers serve two primary functions: DNS host and resolver. DNS hosts possess domains’ zones and answer queries using DNS records from those domains. Changing the zone changes the host.
On the other hand, a resolver is a DNS server that forwards requests to other DNS servers for records from their zones to respond to incoming requests, known as recursive requests.
Why Do Resolvers Cache DNS Records?
Since most DNS records hardly change, most resolvers cache or temporarily store previous search results. If the resolver receives similar requests, it responds with cached results, saving network traffic and reducing domain latency until the cached data expires.
Time to Live (TTL) and Remote Caching
The Time to Live (TTL) is a value specified in seconds that define the duration over which a DNS record should be cached by the resolver. To reduce the propagation time, reduce the TTL value before making changes. However, some ISPs configure their resolvers to ignore the TTL value specified in the record, cache it for a length of time they choose, or up to 72 hours.
Note that irrespective of your custom TTL records set in cPanel, they will not affect propagation time during DNS changes.
Browser Caching and its Effects on DNS Propagation Time
Browser caching is not related to DNS but can still affect the visibility of changes made to DNS settings. Browsers cache previously accessed page content, thereby displaying the older version of the site content. You can clear your cache to receive a fresh copy of the content from the server.
In conclusion, DNS propagation is the period it takes for domain information to synchronize across the internet after DNS changes. The duration of the propagation time depends on several factors, including geographical location, internet service provider, and TTL. Knowing how DNS works and the role of DNS servers in caching DNS records can help users understand how changes made to their DNS settings can affect their web accessibility.