DNS in Windows Server 20003

Litmus Test:  Can you troubleshoot DNS?

Professionals take the time to master their DNS settings

Amateurs use WINS where ever possible and avoid DNS

• Domain Name System (DNS)
• Windows Internet Name Service (WINS)

Domain Name System (DNS or DDNS)

Way back in the days of NT 3.5, DNS was an afterthought and relegated to the option pack.  By the time of NT 4.0, DNS, was a useful if peripheral service installed from the Windows Components.  Nowadays with Windows Server 2003, you cannot even install Active Directory without being an expert in DNS.  During these ten years, WINS has steadily declined, until now it only has a very minor role for Windows 98 clients and some Exchange servers.

At its simplest, DNS is responsible for mapping IP addresses to machine names.  For example in, the DNS database there could be a host record (Type = A) for a machine called London with an IP address of 192.168.0.230.

To truly master DNS you must invest time in the learning the terminology and practice configuring, Reverse Lookup, Zone, Active Directory Integration and other specialist DNS settings.

In Windows Server 2003, DNS can dynamically update its own host records - hence the acronym DDNS.  This overcomes a limitation of DNS in NT 4.0 and allows WINS to be phased out in pure Windows Server 2003 networks.  The only real use of WINS is for organizations with distributed Exchange servers.

DNS and Active Directory

DNS holds SRV or Service records which enables desktop computers and servers to find domain controllers that are providing specific services.  For example, Global Catalog and Kerberos are need for logon authentication; DNS returns the IP address of domain controller offering those services.

By integrating AD and DNS you reduce network traffic because only new or changed records are updated.  This is known as incremental zone transfer (IXFR).  In NT 4.0, the whole database was send over the network even if just one record changed.

How to change to AD zones?  Right click the DNS Zone, Properties, General Tab.

For troubleshooting DNS

• Check out the new Monitoring tab; right click the DNS SERVER, Properties.
• If DNS is not working, revert to the Host file (Winnt\system32\drivers\etc\hosts

See much more on DNS here

DNS is a huge topic, as an MCT trainer, I can thoroughly recommend TrainSignal because they provide practical hands on training.  In particular, I like the way TrainSignal cover all learning methods, instructor lead, video and of course text material.  You can either take one module, for example DNS or go for a combination of modules.  Learn more about DNS 2003 here

Windows Internet Naming Service (WINS)

Litmus Test: Professionals phase out WINS

WINS is a Microsoft method for resolving names to IP addresses.  As you have probably guessed I do not like WINS!

WINS is no longer needed in a pure Windows Server 2003 and  XP networks.  This is because DNS can handle the name resolution and find all the resources XP and W2K Pro need.  However WINS still has a role in enabling Windows 9x clients to find their logon servers.   To be fair, WINS has always allowed dynamic updates, but with DDNS clients can automatically change their IP registrations in DNS.

Footnote:

WINS will be phased out in Exchange 2007 and Longhorn.

See much more on WINS here

Another of Guy's Litmus Tests - Performance Monitoring

Professionals install ipMonitor (40% off until Sept 26th)
Consequently they can see instantly which servers are short of resources, and which are running smoothly.  

Amateurs
Keep their fingers crossed that the servers have enough memory and disk space.

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