A nice example to explain that in a modern way is our phone directory on our mobiles. If we were storing only the actual numbers and not number against a name it would be impossible to find someone’s contact number. In addition when we tap on someone name it calls his number. That is pretty much how DNS works. Internet infrastructure and services are built on IPs (internet protocol) . IPs are numbers in order for us to be able to write a name in our browser’s address bar and fetch the number that will connect to that service we use DNS records.
The commonly used DNS record types are: Nameservers (NS) , glue records, A records, AAAA record, CNAME, MX and TXT records.
Focusing on the most important ones that are needed for most of the basic operations any technical person in the IT industry should realize that with out nameserver record a website will simply not work.
The NS record is stored in something called TLD ( top level domain) server. There countless servers for different domains like .com, .eu .gov etc. Your NS record is with the company you bought your domain from (also known as your domain registrar). You normally have at least two of them.
NS records look something like this.
They are like a website URL, but Instead of linking to a website, they link to the domain names authoritative nameservers. The authoritative nameservers store most of your DNS records with a few exceptions such as NS and glue records. When you buy a domain name it normally has some default NS records managed by the domain registrar.
You can use the domain registrars authoritative nameservers to add other DNS records such as a CNAME or A record. However, as soon as you change NS records to point somewhere else any DNS records added with the domain registrar will be ignored. In a sense NS records take over any possible domain pointers.
The A record is used to point the domain name at one or multiple IP addresses. An IP address looks something like this 52.125.224.12. As explained before an IP is where a website/service lives. There further setting when adding an A record, name, destination, TTL.
The name field can take 3 different values. When ‘@’ is assigned it means that that record will affect the next level of domain. For example @ mvpcloudtech.co.uk actually points at mvpcloutech.co.uk its self. An “*” acts as a wildcard so anything goes when an asterisk is used. Last but not least is a prefix. For example if the A record value is lab for record mvpcloudtech.co.uk that means that lab.mvpcloutech.co.uk will point to the destination value in the destination field. Finally TTL is the time to live. The TTL indicates how long until your computer, or resolver has before it should recheck with the authoritative nameserver. For example if you set the TTL to be 5 minutes it would take 5 minutes for all the computers in the world to use your new setting.
A records and NS records are the most important ones for most of the things we do in Azure. There are more with in our industry, TXT, names etc. that are equally important . But most of the content of this blog will refer to A records or NS records,
