Dynamic DNS can be very useful. You can use it to host your website on your own servers. That’s where parts of my website come from. Currently I use No-Ip for my dynamic DNS needs. The service works great, its simple to use and very effective. My ISP is verizon fios and all though my IP is dynamic it doesn’t change as often as some ISPs do. Sometimes my IP won’t change for months but in case it does no-ip has me covered updating the DNS within 5 minutes.
Some routers have dynamic dns built right in. For example the new business Cisco routers have No-Ip in the firmware. But for those of use that don’t have a router that has it built No-IP has a program that you install on your server and it check for your external IP every 5 minutes and if it changes reports that change to NO-IP servers. To see how that works no-ip created a diagram to show that you can find that below. (Click to Enlarge)
Now No-IP is not the only way of doing this another popular service it DYN DNS. Now I have never used them but I hear that I works mostly in the same way as no-ip does they both have client software that monitors your IP and reports it when it changes.
For me No-Ip has better pricing, for the initial plan no-ip is cheaper than Dyn DNS starting at Free. Now it has some limits you can not use your own domain name with the free version but you can use the sub domains they offer. You can only have 3 host names but the IP needs to change at least once a month and you may need to confirm your account every 30 days, but it still is free. No-IP offers a enhanced version that gives you more domains to choose from and you more hosts, you also you do not have to confirm your account every 30 days. They also offer one more plan which is Plus it has 50 hosts and more control you can also use your own domain names. Dyn Dns has a starting plan of 20 per year but to what it looks like you only get one A record and one MX record. The main thing I don’t like about dyn dns is that they limit your DNS queries per month No-Ip has no limits on that.
No-IP doesn’t just offer DNS they offer Managed Mail, Server Monitoring, SSL Certificates, Squared DNS.
In conclusion If I were picking a DNS provider I would definitively go with No-IP because they offer like everything you need to run your own servers without have to spend extra money on your ISP bill just for a static address.