DNS stands for “Domain Name System”. It relates IP addresses to their corresponding names, specifically, domain names. For example, when you enter google.com, the DNS looks for the corresponding IP address for that particular domain name and returns the address.
There are many DNS servers, and they attempt to keep their information up to date. They do this on a schedule determined by each particular server. Therefore, when a record in the DNS system is changed, there is a delay in updating all DNS servers across the Internet. This delay is often called “propagation”.
Each domain name can have different kinds of DNS records. Each kind of record has a different use. For example, the MX record defines the server that manages email, but it can be different from the server that manages the website (defined by the A record).
- The A record is the most basic kind. It indicates the actual IP address of the domain.
- The canonical record (or CNAME) defines one domain as an alias of another domain.
- It can be used to associate a subdomain (e.g., subdomain.google.com), to an existing domain name record.
- The MX record defines the mail exchange server or servers that handle email for the domain.
- NS defines which Name Server is authoritative for the domain.
- It defines what server to use as the “ultimate” answer to a DNS request.
When you change the company that hosts your website, you need to let the Internet know that the address associated with your domain has changed–just like when you let the Post Office know that you’ve moved to a different address.
Most of the time, the authoritative NS records are set at the domain level. Thus, if you change hosting companies, you may have to update the nameservers at your domain registrar to reflect it.
In other instances, you might host your email with one server and your website with another one. In that case, if you move your website from one host to another, you have to update your A record but leave your MX records intact.
When you change your DNS zones (records) you’re presented with a form that asks for the following information:
- The name of the record: This is the domain name that you’re defining, in the form of yourdomain.com. NOTE: That last dot (.) it is part of the record and must be included.
- TTL: This stands for Time To Live. This is the time in seconds that it will take for this record to refresh. A commonly used Time To Live is 4 hours (14400 seconds).
- Type: The type of record that you are defining: A, MX, CNAME, TXT, NS or others.
- Record: The actual IPV4 (or IPV6) address where the resource is to be located. Since most hosts still support only IPV4 records you will be defining an address in the following form: 000.000.000.000 – four groups of three numbers separated by dots.
We hope you now have the introduction you need to update your DNS records. However, since this information is sensitive and can break your website, email and any other online resources, you may want to have a pro do this for you. AndiSites can make these changes quickly and without costly mistakes. Please don’t hesitate to contact us today!