What is DNS Propagation

When DNS changes are made to your Domain Name Records you need to wait for propagation to complete. Propagation can take from a couple of hours up to two days.  One person may see your new website while others may see the old one and some may even be presented with an error page saying "Server not found"

DNS stands for Domain Name System.

Anytime you try to access  a domain name, you are using DNS.

Your request for "yourdomain.com" goes to your local DNS server. Your local DNS server checks to see "if it knows" what IP address that domain points to. If it does, then it provides you this information. If it does not, then it sends a query to the Root DNS servers.

1. When a domain is registered, its DNS records are added to the Root servers. The Root servers tell your local DNS server which DNS servers are Authoritative for your domain.
     
2. Your local DNS server then queries the Authoritative DNS server, and the Authoritative DNS server tells your local DNS server what IP address the domain is located at or what any needed records point to.
    
3. Your local DNS server then caches (makes a copy of) this information. This caching process is essential: not only does it speed up future queries, it also reduces the load on the Root servers. It is this caching process that leads to propagation. You may change the DNS records for your domain, but the local DNS server cache is still to be updated with the new information.

Root Servers

The authoritative name servers that serve the DNS root zone, commonly known as the “root servers”, are a network of hundreds of servers in many countries around the world.

So what is propagation

Propagation is the time taken for...

1. The worldwide Root Servers to become aware of DNS and Name Server Changes for your domain and..
   
   
2. Your Local DNS Server (usually administered by your ISP) to become aware of DNS changes for your domain name in order to refesh it's cache.