For more information check out this link, you can track your DNS point here https://dnschecker.org/ and get more information, I have referenced some of the information from this website below.
WHAT IS DNS PROPAGATION?
DNS propagation is the time DNS changes take to be updated across the internet on the globe. It can take up to 72 hours to propagate worldwide. You can check your DNS propagation results from here.
WHAT IS DNS RESOLUTION?
DNS resolution translates the domain name into the site’s IP address. You need a site’s IP address to know where it’s on the internet. A website could have IPv4 or IPv6 addresses or both. Where the IPv4 address comes in the form of an A record and the IPv6 address comes in an AAAA record.
HOW DO DNS RECORDS PROPAGATE?
When you update your DNS records, it may take up to 72 hours for the changes to take effect. During this period, the ISPs worldwide update their DNS cache with new DNS information for your domain.
However, due to different DNS cache level, after DNS records changes, some of the visitors might be redirected to the old DNS server, for some time, and other can see the website from new DNS server, shortly after the changes. You can perform the A, AAAA, CNAME, and additional DNS records lookup.
WHY DNS PROPAGATION TAKES TIME?
Suppose you changed your domain’s nameservers, and you requested to open your domain on the web browser. Your request will not go to the hosting directly.
Each of the ISP nodes first checks its DNS cache, whether it has the DNS information for that domain. If it is not there, it will look it up to save it for future use to speed up the DNA lookup process.
Thus, the new nameservers will not propagate instantly – ISPs have different cache refreshing levels, so some will still have the old DNS information in their cache.
But if after that time interval, still, your new DNS changes are not reflecting, then you go for a DNS health check to ensure that your DNS changes are up to the mark and are following the standards.
WHAT IS DNS FAILURE?
DNS failure means that the DNS server cannot convert the domain name into an IP address in a TCP/IP network. That failure may occur within the company’s private network or the internet.
