What is DNS Propagation?

DNS propagation is the period of time it takes for an update to the nameservers of a domain to take effect – usually between 24 – 72 hours.  This is the period of time it takes ISPs (Internet Service Providers) to spread your update throughout their caches around the world. Due to DNS caching at different levels and times some website visitors may see an old page during this time, while other users may see the new update immediately. This is due to DNS caches at different levels. Lets take a moment to look at why this change can take so long and a way to somewhat bypass the propagation period.

 

Why Does Propagation Take So Long to Complete?

This is a very common question from anyone who has ever hosted a site on the internet. When you use a web browser to access a website, your query is passed off from node to node until it reaches the destination server. Each one of these nodes is typically owned by an ISP (Internet Service Provider) and they may update their individual caches at different times.

Imagine trying to call your favorite pizza place using a phone book from 1998. If the pizzeria’s number has not changed since 1998 then you could reach them using that number without an issue. However, if the number has changed, and you don’t have a current phone book you more than likely will not be able to reach them.

Propagation is very similar to this analogy in that the pizzeria is a website, the phone book is an ISP node and the year in which the phone book was released is propagation. But there is a way to somewhat bypass the propagation time all together using a little DNS magic and A records. Let’s take a look at how this can be achieved.

 

How to Bypass DNS Propagation

This method ONLY works if you have NOT changed your nameservers during a website transfer. If you have already changed your nameservers it’s best if you wait for propagation to complete, as making multiple changes could delay the propagation time. You can check the status of a domain’s propagation by using a wonderful online tool called whatsmydns.net. To reduce/bypass propagation time you simply need to do the following:

 

  1. Set an A record at your current hosting provider or registrar to point your domain to the new IP address of your new host
  2. Set the TTL (Time to Live) to value such as 300 seconds
  3. Wait for approximately an hour, check to ensure that A record has changed and then change your nameservers to your new host

 

Once this process is complete, your domain should begin resolving the same content regardless of if the user’s browser is pulling the site up from your old host or the new one.

 


Share:

Leave a Reply