Today – I’d thought we’d take a moment and try to demystify Dynamic DNS for the common man (or woman). For the non-technical, and even some of the technical – Dynamic DNS is not necessarily the easiest thing to understand at the surface. Understanding the need for it may be even more of a mystery.
Let start by talking about the main tasks that people use Dynamic DNS (DDNS) for, or in other words – what problems does Dynamic DNS solve for us? We’ll start at the top with the end all solution to a problem, and then work back down to describe how DDNS was used to solve the problem. The most common uses for DDNS today are to gain access of a computer, or IP camera in a location that is remote to you. IE the home, a remote office – or anywhere that you are not at the moment. More commonly, folks are looking to use remote control programs (IE VNC or Windows Remote Desktop) to access a home computer from work, or they often looking to host a web site or IP camera at home and access it from the Internet just like any other website.
For the purposes of understanding – I would like to compare how the Internet (and DDNS) works to our modern-day telephone network, as there are many similarities. Ok – let’s roll up our sleeves and go!
Every computer connected to the Internet has a numeric “phone number” just like every telephone does in the telephone network (worldwide). This is called its “IP Address”; “IP” standing for “Internet Protocol”. However, there is no published “phone book” of computer numbers, like there is for telephones. What the Internet uses in place of a phone book is a worldwide, distributed, electronic database known as the “Domain Naming System”, or “DNS”. Think of it this way – if you had a phone, but no phone book – you would have no way to “look up” someone’s phone number that you wish to call. A phone would not be very useful without a phone book. Also humans are good at remembering names, not necessarily numbers, so phone books are organized alphabetically by name. So, if I would like to find the phone number of a person or place that I do not know, I turn to a phone book and look it up alphabetically, by name.
For the same reason – computers that desire to be “looked up” by those require a name to allow finding it to become easier. These names that computers use on the Internet are known as their “Domain”, or “Domain Name”. Examples of this are www.dns2go.com, and bobsmith.d2g.com. Instead of a printed phonebook however, the find the IP Address (phone number) of a computer is provide by DNS automatically when an Internet application (like a web browser, or Remote Desktop client) performs a “lookup” while trying to connect to a domain name.
Now – we are entering the most important part of this post; understanding the difference between DNS and DDNS: By rule in order for a computer to have a domain name it must also have what is considered a “static” (non-changing) IP Address. What this means is that as your computer is connected to the Internet, turned off/on, and rebooted – it always has the same IP Address (just like your phone number stays the same). You could imagine that a phone book can not work if a persons phone number keeps changing, however in the Internet world that happens quite often. Most residential Internet service providers (IE Comcast/Charter, etc.) us a “pool” of IP Addresses to reduce costs, and offer lower cost services to their customers. This means that periodically the computer is assigned a new number automatically through a protocol called “Dynamic Host Control Protocol”, or DHCP. Basically, they may have a 100 customers, but maybe only 50 IP Addresses to use. They anticipate that only 50 customers will be online at any one time, so there is never a problem. Once a computer is done with their Internet session, they put their IP Address in the pool for someone else to use. Are you ready? Dynamic DNS is an added value service that allows a domain name (phone book entry) to be associated to a computers who’s IP Addresses changes from time to time. To use the telephone analogy one more time – is would allow a telephone number to change (like with a disposable cell phone), but the phonebook entry for that person to stay the same. It essentially allows computers using low-cost internet service to have a name just like the big boys.
We’ll go into detail more about this in future posts, but basically the DNS2Go DDNS service does this by loading a small client software on your computer which connects to the DNS2Go severs. The DNS2Go client communicates the IP Address of the remote computer to the DNS2Go servers, and every time that IP Address changes, the users DNS entry is updated.
Why would I need it? Two main reasons: The first reasons is is to give you the ability to associate a canonical (common) domain name to you computer that can be easily remembered. The second reason is it allows you to use low-cost Internet connectivity but still have the ability to also associate a domain name to your computer. Most common uses for DNS2Go today are accessing a computer via Remote Control, Accessing IP Camera’s, and hosting web sites on a home or office computer. Keep in mind that DDNS only provides the name look up service. In order to perform these aforementioned task, there are more requirements to be completed. Once configured however, DDNS can provide an invaluable service to it’s users!
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