The perils of switching registrars

One of our clients unintentionally DoSed themselves this weekend by switching registrars. In what turns out to be an honest mistake on someone’s part, the new registrar set the company’s DNS servers to the registrar’s (pretty standard action), but they didn’t copy the old DNS information from the previous registrar. Effectively denying service to the organization’s mail server (no DNS entry and no MX record), and some websites that generate revenue.

I would suspect that this is a common situation for smaller companies. They decide that they’re not happy with their current registrar for whatever reason, and switch. Unfortunately, not understanding how computers find each other and buying into the “complete hosting solution” packages offered by many registrars. In an effort to prevent other small companies from suffering the same fate, I present DNS, whois, and hosting for dummies.

When you decide to set up a website, there are really three services at play:

1. Hosting – this is where the files that makeup your website reside
2. Domain Name ownership – this is where you buy a domain name (whatsit.com)
3. Domain Name Service – this is buying a service to map www.whatsit.com to your actual website

Computers don’t use hostnames to find each other, they use IP addresses, which are not human friendly. The Domain Name System (DNS) service maps all of the human readable hostnames to computer friendly IP addresses.

When you buy a domain name, you buy from a registrar. GoDaddy.com, Register.com, and Network Solutions are some of the larger registrars. What they do is set up DNS in the top level domain (.com, .org, etc) for you. All that does is say that you own it, and that you’ll be providing your own DNS servers for that domain. You must also tell your registrar who is providing DNS services for you. Oh, you don’t have a DNS service provider yet? Your registrar will helpfully use their own DNS servers for you until you do. These servers will point to some kind of advertising page if someone goes to http://whatsit.com. Don’t worry, unless you’re providing your own DNS services (and if you’re buying hosting, you probably aren’t), you can’t get DNS services until you’ve bought the domain, so you’ll have that ad page there for an hour or so at least.

Next, you’ll buy your hosting, because you’ll need to be able to give them your domain name, and they’ll need to give you an IP address. Once you have the IP address of your server, you can go buy DNS services. However, you’ll probably want to work with your hosting provider to somehow get your website content to their servers.

All of the registrars can provide DNS services (for an extra fee), but there are a few free or inexpensive ones (Granite Canyon is one of my favorites for free, and DynDNS can’t be beat for low cost). You’ll need to give the DNS provider your domain name, and the hostname and IP address of your web server (given to you by your hosting provider). They’ll give you a list of name servers. Now you have to give this list of name servers to your registrar and, finally, people will be able to get to your content on your web site.

As you can see, there are a lot of moving parts, so it’s really common to just let one entity (usually the registrar, but sometimes your hosting provider) handle it all for you. However, if you have more DNS entries, such as for a mail server, the registrar or hosting provider may not know about them, so switching all of these services at once can turn into lost DNS entries. Because, now, your new registrar is listed as the DNS service for your domain, but it doesn’t know about all those other entries you’ve added over the years, and they are simply gone if you didn’t keep a backup somewhere. If these entries aren’t in your DNS, other computers can’t find your computer(s) any more, causing a denial of service (DoS). Even if you choose to have one entity arrange all of these services for you, knowing how it all works will be useful to figuring out what’s wrong when things break.