DynDNS

DynDNS® is one of the most popular DNS hosting services, they provide one of the highest level of services in the industry. DynDNS is the sole Domain Name System (DNS) provider for the .coop TLD. In April of 2006 they received a "Best Buy" rating when they scored a perfect 10 out of 10 rating on Overall Value, Performance and Ease of Use in Consumer Magazine.

DynDNS started in 1998 when they began providing a free Dynamic DNS service to the public. DynDNS is most well known for this service. When subscribers sign up for Dynamic DNS they get an address similar to yourname.dyndns.org. Since 1998 DynDNS has continued to provide popular reliable DNS services worldwide, all of which allow you to map a dynamic or static IP address to a hostname.

While their most popular service is Dynamic DNS, DynDNS also provides other services which allow you to run a home website, ftp server, web camera, or any number of servers which require you to know the external IP address of your home network. DynDNS enables you to access important data while you're at home, school, work, or play.

Their second most popular service is called Custom DNS it works in a very similar way to Dynamic DNS, except you also have the ability to use your own registered domain. Custom DNS also enables you to create virtually unlimited subdomains, and many other additional features and options.

Generally users run one of the available third-party update clients on their computer, and it keeps their hostname up to date with their most current IP address, even if their ISP changes it often.

DynDNS also provides other well known services such as recursive DNS, mail forwarding (which optionally includes virus and spam filtering), mail redirection (to bypass port blocks that may have been put in place by ISPs), SSL certificates, and network monitoring services.

How Dynamic DNS works
Once you setup a Dynamic DNS hostname, the hostname you make will point to your new IP. You can run an update client to keep this hostname up to date 24x7, so you never lose access, even if your IP changes. Where you would normally need a Static IP, DynDNS allows you to save the additional costs of upgrading and allows you to use your Dynamic IP address. You can run your server or network device without a problem with DynDNS. DynDNS users have web, email, FTP and any other kind servers you can think of. The best part of using Dynamic DNS is you no longer have to keep memorizing your new IP address!

How a Dynamic DNS service affects your server
Dynamic DNS providers do not take up any of your server's bandwidth, since no traffic actually goes through them. Any user trying to reach your device will send out an initial DNS query to the DNS provider to get your IP address then after that the traffic goes directly to you. This means there is almost no increase in latency, nor is there any restriction on how the connection can be used, beyond those placed on you by your ISP.

Can a Dynamic DNS service replace my static IP?
In most situations a static IP is not required. A Dynamic DNS service allows your host to be mapped to your IP, even when your IP changes, however, there can be some issues depending on your situation; some of which are outlined below:

1) If your IP changes while you are connected to your server, you may lose the connection and will need to reconnect.

2) While most software and hardware will work with a hostname, some older equipment requires an IP and will not work with a hostname. In those situations a Dynamic DNS service won't help.

3) Many email providers block mail from servers that have dynamic IP addresses. To get around this issue you would need to use an outbound mail relaying service to allow you to send out mail through their servers, such as MailHop Outbound.

4) Many satellite ISPs place users behind a NAT, which means they do not have a publicly accessible IP; unfortunately this prevents them from running any kind of server.

5) You can not setup Reverse DNS using a dynamic IP, only a static IP. This is because your IP is actually owned and controlled by your ISP.  In the event you need Reverse DNS to sendmail you should upgrade to a static IP address or send mail using a SMTP smart host, such as MailHop Outbound.