Dynamic DNS (DDNS) is an addition to the DNS
standard. Dynamic DNS defines a protocol for dynamically updating a
DNS server with new or changed values. Prior to DDNS, administrators
needed to manually configure the records stored by DNS
servers. DDNS allows this to happen automatically for
continually changing IP addresses, without the need for human
intervention.
In simpler terms, DDNS allows a fully qualified domain
name (FQDN) that doesn't ever change to be associated with a
dynamically assigned IP address that can change quite often. For
example, say you wanted to name your computer
DarthVader.iu.edu but you were required to use
DHCP (as
computers are on the Indiana University network, except for servers,
or mission-critical or special-applications workstations). Even if
you enter DarthVader in the "Computer Name"
field of your
computer properties, DNS servers anywhere would know you only by the
FQDN that is associated with the IP address you are assigned; for
example, at IU, if DHCP gives you an IP address of
156.56.0.1, your computer's name to the entire
Internet
is not DarthVader.iu.edu, but
156-56-0-1.dhcp-bl.indiana.edu. This will be
the case no
matter what you enter into the "Computer Name" field in your settings.
However, DDNS changes that. 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 the IP your
computer
receives every time.
The DDNS service implemented on the IU network works for
Windows 2000
and XP
Professional, the server
versions of Windows 2000, and 2003 Server as well. It will not work
for Windows
95, 98, 98SE, Me,
NT 4.0, or XP
Home Edition, nor will it work for
non-Windows operating systems, such as Mac OS X,
Linux, or
BSD. This is
because IU's DDNS service
works through the Active Directory domain controllers, and a computer
must be joined to the IU Active Directory to take advantage of it.
If you have a non-Windows operating system, or are not joined
to a
domain, it is possible to use a third-party DDNS service, such as Dynamic Network Services,
Inc., PlanetDNS, or others. You
will
have to conduct an online search or contact one of the many providers
for instructions on how to use their service with your computer (These
providers are named as examples only; UITS
does not
recommend or endorse any third-party DDNS service.) Keep in mind that
although the 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 properly.
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 IT Security
Office (ITSO) recommends that you normally run your Windows
computer as a member of the Users Group, not as an administrator or a
member of the Power Users Group. For more information, see In Windows 2000 and later,
why should I avoid running my computer as an administrator or Power
User? For tasks requiring administrative access, you can gain
it quickly using the Windows Secondary Logon
service. For
more information, see What is the principle of
least privilege?
- Right-click
My Network Places
and click
Properties.
- Right-click
Local Area
Connection and click
Properties.
- Select
Internet Protocol
(TCP/IP) and click
Properties.
- Click the
Advanced...
button.
- Click the
DNS tab. Next to
"DNS suffix for this
connection:", type ads.iu.edu .
- Check
Register this
connection's addresses in DNS.
- Check
Use this
connection's DNS Suffix in DNS
registration.
- Click
OK, then
OK again, and
then
Close.
Now your computer will dynamically register itself with the IU DDNS
servers.
Again, this is how you set DDNS up with a Windows computer
joined to
the IU Active Directory. If you use a third-party DDNS provider, the
instructions will almost certainly be far different; in that case,
follow your provider's directions rather than the ones here.
Also see:
