How can Dynamic DNS help you?

What is DNS? (domain name system)

Let me put it in terms most people can relate to.  The phone book.  When you want to call someone who’s phone number you don’t have, you grab the white pages (or yellow if it’s a business) and then you find their name and listed phone number.  You now have a number to call and so then you dial it on your phone.  In the world of networks, the internet being the biggest, connections are made by IP addresses, not the URL (i.e. technopotomus.com).

With DNS, it’s all taken care of for you.  Your computer is programmed with a DNS server either statically or dynamically when when it obtains its temporary IP address.  Now when you enter a web address that your computer does not know the IP for, it asks the DNS server what the IP address is for the URL you requested.  It then will tell your computer the number and your browser then uses that IP address to communicate with the web server.  Much like a 411 operator can connect your call after you ask for someones number.

The benefit of this to you and I is that we don’t have to remember the IP address for google.com, ubuntu.com or technopotomus.com.  We just have to remember their name, and that’s alot easier.  Especially when devices start using IPV6, you do NOT want to remember those numbers.

What is dynamic DNS?

Now if you want to connect to your home network from work, your buddies house or wherever else you have an internet connection, how are you going to do that?  Most people do not have a static IP address for their home internet connection.  Why?  Because your ISP has a pool of addresses and when your computer or your router logs into the internet with your local provider, it gives your device a temporary IP address and then when you disconnect, the IP address goes back into the pool.  The next time you connect, your IP address is likely to be different from the last time.  For most people, this is no big deal.  It’s been that way for some time without many people knowing, or caring, just so long as they can surf the net.

Again, how are you going to connect to your home network from work?  Dynamic DNS!!

How Dynamic DNS can be of help to you.

If you have your own domain name, this can work.  If you don’t, this can still work.

Keep in mind now there is a slew of Dynamic DNS providers.  Most of them provide this service for free.  Hey what could be better than that?  I suppose if they paid us to use their service, that would be better, but lets keep things on the side of reality here.  Most new household routers also provide a spot where you can enter your Dynamic DNS information (after you’ve signed up with a provider).  If you don’t have a router that will accommodate, or you’d rather not use a router for whatever reasons, you can install a small client on your computer which will do the same thing for you.

How to get service.

DynDNS is just one service.  I am using them as a sample only because that’s a service I have used an am familiar with them.  I imagine the others will be as simple to setup and use.  Once you create an account, you get to chose from a variety of domain names such as blogdns.com, dnsalias.com, hobby-site.com, is-a-geek.com and many, many others.  You then chose your 3rd level name to append to the front of your choice (if it’s available).  So imagine choosing birdhouses.hobby-site.com, then you can refer to your network as such.  And if you chose to setup a web server, you can give this URL out to direct traffic to your website.

Your next step is to enter your login name, password and your new hostname into your router.   If you chose to use an IP update client for your computer, make sure the service you chose has a client for your operating system.  DynDNS has a client for Linux, MacOS and Windows.

How does it work?

Once you have completed your configuration, go make a sandwich or two and eat them.  It will take some time to update.

The process now is that your router or client will periodically connect to your DDNS service with username and password.  When this happens, it grabs your IP address from the packets and now assigns your hostname with your IP address.  (don’t worry if your client is on a machine behind a router, the DDNS service will still obtain your public IP address)

Once the update is complete, requests for birdhouses.hobby-site.com will route to your IP address.  Keep in mind though, that if you try to connect TO your public IP address FROM your public IP address, it will not work. Apparently routers don’t like to try to send out requests for something that it knows is NOT OUT THERE.  I found that out when my DDNS service did not work, then I gave it one last try from work  and it was working.

Be Careful.

Keep in mind now, that if you publish your hostname, it will be more noticeable to others, perhaps people wanting to compromise your network.  Be careful what you put on there, and what security measures you need to take to keep things secure.  If you log into your computer, be sure not to use TELNET.  It sends everything in clear text, so if you log into your computer remotely, anyone using a packet sniffer that comes upon your transmission will see your IP address, username and password.  Wow, now you’ve got a big problem.  To avoid that, use Secure Shell (SSH).  One such client is putty.  You will however have to make sure that you have an SSH server installed on the device you plan to connect to.

So when your IP address changes, for whatever reason, you’ll never be out of your system or users denied access to your website.   As your IP address is Dynamic, so will your Domain.  Cheers.