There is nothing more frustrating than launching a new website or needing to make a change to DNS and it does not work quickly. Here's why.
We call the time it takes for changes to be reflected Propagation. Since DNS servers have to update other servers around the world with the new information, propagation can take a long time and is not instant. The general rule is propagation takes 24 hours to complete worldwide. However, in some cases, this can take up to 48 hours, depending on DNS record TTLs.
It is important DNS be completely propagated before adding the changes to a live website, or a CDN, because if propagation is incomplete, users can have issues getting to the website. To avoid these issues, it is always good practice to check propagation status with a web tool like whatsmydns, to ensure visitors have the best overall experience. Once the servers have been updated worldwide, you will see green checkmarks and the IP address of an A record, or the linked Fully Qualified Domain Name of a CNAME record.
If you are having issues with DNS please view our article that teaches you how to debug common DNS problems.