What is DNS
What is DNS and why is it important?
The Domain Name System (DNS) translates domain names understood by you and me into IP addresses which are understood by computers and networking equipment the world over. An easy to understand analogy that is used often to explain the Domain Name System is that it serves as the "phone book" for the Internet by translating human friendly computer hostnames into IP addresses such as 220.127.116.11. This happens every time you use a domain name, whether you are viewing websites, sending email, or using any Internet related service. Essentially DNS is involved with everything on the web and is the glue that holds the Internet together. Without DNS the Internet simply would not work.
How does DNS work?
When you visit a domain such as www.loaddns.com, your computer follows a series of steps to turn the human-readable web address into a machine-readable IP address. This happens every time you use a domain name, whether you are viewing websites, sending email, or using any Internet related service. Essentially DNS is involved with everything on the web. The 7 steps below explain the DNS process.
1. Request Information
The process begins when you ask your computer to resolve a hostname, such as visiting http://www.loaddns.com. Your computer will first look to its local DNS cache. If your computer doesn't have the answer, it will then execute a DNS query to find out.
2. Query the Recursive DNS Servers
Your computer will first try to find the information you are looking for in its cache. If it is not in its cache the computer then queries your ISP's recursive DNS servers. Your ISP’s recursive DNS servers execute the DNS query for your computers. Your ISP’s Recursive servers have their own caches, so most of the time the DNS process will end here, and the information is returned to your computer and thus to you.
3. Query the Root Nameservers
If the answer isn’t found by your ISP’s recursive servers they will then query the thirteen root nameservers. The root nameservers don't have the answer, but they will send your query in the right direction to find it.
4. Query the TLD Nameservers
Reading your domain from right to left the root nameservers will direct our query to the proper TLD nameservers as an example we will use .com and .net. The .com and .net nameservers don't actually have the information, but they will send us to the servers that do, the authoritative nameservers.
5. Query the Authoritative Nameservers
The root nameservers direct the query to the authoritative nameservers for that domain. For a client of ours using LoadDNS Deluxe our Enterprise (our Anycast service) the nameservers are ns1.anycast.loaddns.com and ns2.anycast.loaddns.com. Our nameservers know all the information about our clients specific domain. The information is in the following records A, CNAME, NS, MX, TXT, SRV, PTR, AAAA and SOA.
6. MX Record Retrieval
The authoritative nameservers store the MX information for the client domain. The MX record is retrieved by the recursive nameservers, the record is then stored in its cache. Records have a time-to-live (TTL) value, which can be set in the LoadDNS administration system. As long as the TTL value has not expired, the recursive servers will have the information. Once the TTL does expire the process in steps 1-5 above will need to happen again.
7. The Query is Resolved
Your computer recieves the information from the recursive servers and stores it in it's cache. This process happens as fast as the managed DNS provider that you use can resolve queries. At LoadDNS are proud to say that our average query resolution time is the fastest you will find of any managed DNS provider in the market today.