While the concept of DNS is simple, the technical details are rather complex. Unless you work with DNS on a regular basis, the intricacies are probably a mystery. Generally once DNS (for your website, server, computer etc) is configured, we forget about it and it just works – everyone is happy. But things happen and every once in awhile we need to look up our forgotten settings and make changes or fix something.
Some of the common reasons we need to change DNS
- Server failure requires us to move or restore a website or service to a new machine.
- Networking changes
- Moving service providers
- Security threat or some type of attack from the network
Out network is happy enough working with IP addresses but of course people prefer names. In order to get our domain name pointed to the right P address we need to change our DNS. Once changes, DNS need to propagate around the Internet so that everyone knows about those changes. The guidelines is that these changes can take up to 48 hours to propagate, however it is often much faster than that.
Once we make a DNS change it is often a frustrating wait to see them take effect. Worse, if you are confident you made the change correctly, you might not know if you are awaiting the DNS change or if you did it wrong! Fortunately there is a free service that let you check on the status from multiple locations around the world. Just plug in your domain name and it will show the status of your DNS propagation.
whatsmydns.net is an online service that allows you to instantly perform a DNS lookup to check a hostnames current IP Address and other DNS information against a selection of random name servers around the world. This is especially useful to check the current state of DNS propagation after making changes to your domains zones.