DNS Propagation – Why Domains Take Too Long?
The negative part of the caching process is that different ISP update the caches diferently; some 24 hrs, 36hrs and even others go to 72hrs. The rate of updating the cache between 24hrs to 72hrs is what we call DNS propagation. When the process is complete everyone will now see your website. Because the caching updating differ between ISP servers, the propagation duration is therefore said to vary between 24hrs to 72hrs for DNS and IP addresses to completely take into effect