Managed DNS basics

The only thing that we should remember to visit our favorite website is its domain name - something like yourdomain.com. But our home (or office) computer should know more computer-oriented address to start data exchange with the website. This computer-oriented address is known as IP-address and looks like 123.134.156.178 - four numbers from 0 to 255 separated with dots. Thanks to DNS (or Domain Name System) we shouldn't remember all those numbers.   When you visit website you don't need to know how DNS works, all the work is carried out by your computer software and DNS servers. Most of the hosting providers are also hiding DNS fine tuning from their customers, but if you will learn a little about DNS records structure you will be able to control your website more effectively: setup subdomains quickly, use your own name servers, share the load between different physical machines. There are several types of DNS records and most of them are essential to make your website operate properly:

• A (Address) record is the way your website telling DNS servers all over the world that he is sitting on this particular machine by assigning domain name to machine's IP-address. A records should be assigned to your domain and every subdomains you have.
• NS (name server) record contains address (human friendly one, not IP) of the name server which is responsible for your website. Usually, there are two such servers - primary and secondary - so most of the domains have two NS records like ns1.yourdomain.com and ns2.yourdomain.com.
• MX (mail exchange) records are responsible for mail delivery. When somebody sends you a message his mail server is looking for MX record for yourdomain.com (usually it's look like mail.yourdomain.com) and than looking for A record for mail.yourdomain.com to figure out IP-address of the machine that serves mail for your website.
• CNAME (canonical name) record is often used to create domain name aliases. For example, if you have two domain names and want to use them both for your website you can create a CNAME record to point yourdomain-2.com to yourdomain.com so the visitors who have typed yourdomain-2.com in their browsers will see the same pages as if they have typed yourdomain.com.
• TXT (text) record is useful to assign any comments to your domains or subdomains. Up to 256 characters of plain text for information purposes only.
• SOA (Start of Authority) record holds several vital parameters for entire Zone such as primary DNS server name, email of the person who's responsible for Zone maintenance, serial number (updated automatically), refresh, retry and expire interval for secondary DNS server, and default TTL value.