What is Dynamic DNS (DDNS), and how do I set it up at IU?

Dynamic DNS (DDNS) is an addition to the DNS standard. Dynamic DNS updates a DNS server with new or changed records for IP addresses without the need for human intervention.

DDNS allows a fully qualified domain name (FQDN) that never changes to be associated with a dynamically assigned IP address that can change quite often.

For example, you want to name your computer DarthVader.iu.edu but you are required to use DHCP. Even if you enter DarthVader in the "Computer Name" field of your computer properties, DNS servers anywhere would know you only by the FQDN associated with the IP address you are assigned. At Indiana University, if DHCP gives you an IP address of 156.56.0.1, your computer's name to the entire Internet would not be DarthVader.iu.edu, but 156-56-0-1.dhcp-bl.indiana.edu.

If you use DDNS, then the DNS servers will know not to assign you the normal DHCP FQDN, but will properly associate DarthVader.iu.edu with your computer's current IP address.

At IU, DDNS works for Windows Vista, XP Professional, Windows 2000, and the server versions of each (2000, 2003, 2008). It will not work for the Home editions of Vista or XP, versions older than 2000, or non-Windows operating systems, such as Mac OS X, Linux, or BSD.

If your operating system is not supported, or if you cannot join to the ADS domain, you can use a third-party DDNS service, such as Dynamic Network Services, Inc., PlanetDNS, or others. For details and instructions, see their web sites; UITS does not recommend or endorse any third-party DDNS service.

Although DDNS is an official addition to the DNS standard, not all ISPs refresh their own DNS servers' data often enough to reflect daily changes, so some users may still run into trouble accessing your DDNS-configured FQDN. That would not be the fault of your DDNS service provider; it would be a problem caused by the ISP not updating its DNS tables quickly enough.

To set up your Windows computer to use Indiana University's DDNS service, follow these steps while logged in as an administrator:

Note: At Indiana University, the University Information Security Office (UISO) recommends that you normally refrain from running your Windows computer as an administrator. For more, see What is the principle of least privilege?

Windows Vista

1. From the Start menu, click Network.
   
   
2. From the toolbar of the window that opens, click Network and Sharing Center.
   
   
3. In the Network and Sharing Center, on the left, click Manage network connections.
   
   
4. Right-click Local Area Connection, and then click Properties.
   
   
5. Select Internet Protocol 4 (TCP/IPv4), and click Properties.
   
   
6. Click Advanced... .
   
   
7. Click the DNS tab. Next to "DNS suffix for this connection:", type ads.iu.edu .
   
   
8. Check Register this connection's addresses in DNS.
   
   
9. Check Use this connection's DNS Suffix in DNS registration.
   
   
10. Click OK, then OK again, and then Close.

Windows XP and 2000

1. Right-click My Network Places, and choose Properties.
   
   
2. Right-click Local Area Connection, and then click Properties.
   
   
3. Select Internet Protocol (TCP/IP), and click Properties.
   
   
4. Click Advanced... .
   
   
5. Click the DNS tab. Next to "DNS suffix for this connection:", type ads.iu.edu .
   
   
6. Check Register this connection's addresses in DNS.
   
   
7. Check Use this connection's DNS Suffix in DNS registration.
   
   
8. Click OK, then OK again, and then Close.

Now your computer will dynamically register itself with the IU DDNS servers.

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