You're here: How to guides Creating a fixed domain name

How to create a fixed domain name

The problem of a dynamic IP address

In most cases, each time you connect to the Internet you obtain a different IP Address. This scenario is known as obtaining a dynamic IP address from your Internet service provider.

If you connect to the Internet via a dial-up modem your IP address is very likely to be different. If you connect to the Internet via an ADSL modem your IP address may be different. From my experience of using ADSL your IP address can change while you are connected to the Internet. If you connect to the Internet via a cable modem your IP address may be different. From my experience of using Cable modem your IP address never changes while you are connected to the Internet, and rarely changes when you connect to the Internet on different occasions.

Some Internet service providers (ISPs) offer the option to fix your IP Address so that you always obtain the same IP address when you connect to the Internet. However, this option usually costs a little extra to the normal service charges.

I have been using broadband Internet for a few years now and have benefited by sharing my broadband Internet connection with all the computers on my local area network (LAN) using a broadband Internet router. I initially thought that if I left my router connected to my broadband (ADSL or Cable) modem and never powered down both devices that I would keep the same IP Address.

When I had a cable modem I always retained the same IP Address by keeping both the cable modem and broadband router powered up. However, when the cable modem service went down for a period of 12 hours I obtained a new IP address when the service returned.

I now live in an area where cable modem is not available so I have ADSL. My broadband router works with the ADSL modem, however the IP Address changes frequently even though both devices are powered up all of the time. I am no expert on Point to Point Protocol over Ethernet (PPoE), but I suspect the the PPoE protocol that ADSL uses allows a change in IP Address without the loss of service.

So what's the problem with a dynamic IP address ?

Since me and many other people run services on our computers, we want to have a fixed presence on the Internet for the following reasons:

• so we do not have to keep changing HTML pages that reference an IP address that keeps changing (e.g. live web cam streams and live MP3 music streams)
• so people know our "address" on the Internet (e.g. for placing a call with Netmeeting or for logging on to an FTP server, SSH server or Terminal server)

The solution - obtaining a free domain name service

If you are running services from your computer such as a live web cam, live MP3 shoutcast stream, web server, Terminal server, FTP server, or a SSH server then it is essential that you fix your presence on the Internet by using a free service provided by no-ip.com or dyndns.org.

These free domain name services allow your Internet connection to have a fixed domain name (such as wisbey.hopto.org or wisbey.dnsalias.com) on the Internet even if your IP address varies each time you connect to the Internet. These services basically work as follows:

• You register a free domain name (more than one if you want) with no-ip.com or dyndns.com. You specify an e-mail address, username and password during your registration.
• You download and install a small "dynamic update client" (DUC) application on your computer from no-ip.com or dyndns.com. There are many different types of DUC available for the dyndns.org service, which support a number of different platforms and operating systems.
• The DUC application reads your current IP address you have on the Internet and tells the domain name service (DNS) servers at no-ip.com or dyndns.org what your current IP address is.
• The DNS servers at no-ip.com or dyndns.org update your domain name according to the IP address you have.
• Your domain name is up to date.
• If your IP address changes, the DUC application tells the DNS servers at no-ip.com or dyndns.org what your current new IP address is.

Some broadband Internet routers have the dyndns.org DUC application installed on them.