How to Use Dynamic DNS


Using a dynamic DNS can help ensure your home business’s online presence is runs smoothly.

You’ve been building up the computer systems for your home business. It’s reached the point where it’s worth putting them on their own Internet domain. It’s a little tricky, but you can do it.

Here’s the issue. Every device on the Internet has an IP address. It’s a set of four numbers, such as People don’t access the Internet by IP addresses, of course; they use domain names. A Domain Name Service (DNS) maps domain names to addresses; for instance, might have the address

If you’re a big company with a lot of money, you can get a fixed IP address that belongs to your domain. It will rarely change, if ever. But for most of us, there’s a problem: There aren’t enough addresses to go around. If you’ve got an account with an Internet service provider, it allocates an address dynamically to you, using a pool of addresses. It can change at any time.

If you want to register a domain for your home-based system, that’s a problem. The IP address which you have at the moment could belong to someone else in a few hours. Still, there’s a way to do it. Some DNS registrars provide a service called Dynamic DNS.

(There’s another IP address scheme, called IPv6, which eliminates the problem by providing a lot more addresses. It hasn’t caught on universally, though, and till it does you need an old-style, IPv4 address.)

Setting up Dynamic DNS

With Dynamic DNS, your registrar keeps your IP address up to date on its server through all its changes. Your equipment has to notify the registrar of each change. The software that does this is called an update client. There are two ways to set it up.

One way is to have your router act as the update client. Many routers support this feature. This is the simpler approach, since you don’t have to install any software in your computer. You just need to configure it according to your provider’s instructions.

The other way is to have the update client run on your computer. That’s more reliable, since you can install software tailored for or recommended by your provider.

When should you use Dynamic DNS?

Dynamic DNS has some problems. A dynamic IP address can’t be cached as much as a fixed one, so there’s more overhead looking it up, affecting performance. If your client misbehaves, you might disappear from the Internet. Free services are available, but they usually limit you to certain domains or subject you to ads and “nagware.” A paid account isn’t expensive, though.

When does it make sense to use a home-based system with Dynamic DNS, rather than getting a free or inexpensive hosted site? Everyone’s reasons will be different. Here are a few possibilities:

  • You want to access your own computer easily when you’re on the road.
  • You’ve got specialized software which is very resource-intensive or otherwise problematic for a hosted system.
  • You have unusual computer hardware which is essential to what you’re doing.
  • You just like having full control of the host computer.

If you’ve got a specialized service that you want to run on your own equipment, you can still have your website hosted and use a subdomain (e.g., for your unique software. Every subdomain that you control can have a different IP address and different DNS service.

Hosting your own domain means extra responsibility. Any published domain becomes a target for crooks cruising the Internet for sites to attack. You have to be extra careful to configure your firewall and set up strong passwords to keep intruders out.

If you really need your own domain for your own equipment, though, Dynamic DNS is the way to go, and it’s not that expensive or difficult.

SystemsNet provides support and managed services to keep your computer systems running smoothly. Please contact us to learn what we can do for you.

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