DNS Does the Trick

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One way to simplify TCP/IP host identification is to use Fully Qualified Domain Names (FQDNs) instead of IP addresses. An FQDN is the type of name used to identify resources on the Internet to make access easier for humans (such as http://www.microsoft.com). Resolving domain names and FQDNs to IP addresses is a crucial service on TCP/IP networks in general and especially on the Internet, where hundreds of millions of names and addresses can be found. This is where the Domain Name Service - sometimes called the Domain Naming Service or Domain Name System, but always abbreviated as DNS - comes into play.

As with NetBIOS names and IP addresses, the association between FQDNs and IP addresses can also be maintained in two ways:

  • HOSTS file: You can create a HOSTS file on each system. The HOSTS file maintains a local table that associates specific FQDNs with specific IP addresses. When such associations change, the HOSTS file must be updated manually and copied to all machines on a network.

    HOSTS files are not suited for interaction with large IP-based networks, especially the Internet. This explains why HOSTS files are mostly relics of an earlier, simpler era of IP networking. Except as a fallback in case access to DNS fails, no one uses HOSTS files anymore.

  • DNS: Access to a DNS server allows network machines to request name resolution services from that server instead of maintaining name-to-address associations themselves . Although DNS servers must be configured manually, a DNS server can handle the name resolution needs of an entire network with ease. DNS servers can also communicate with one another, so a name resolution request that the local server can't handle can be passed up the FQDN name hierarchy until it reaches a server that can resolve the name into an address or indicate that the name is invalid.

The Internet includes tens of thousands of DNS servers. ISPs manage many of these DNS servers; others fall under the control of special top-level domain authorities. To stake out an Internet presence, you must obtain a unique FQDN through the InterNIC (or let your ISP do it for you). After you obtain this name, it's associated with a special root IP address in some DNS server (probably at your ISP, unless you decide to set up a DNS server of your own).

Whether to DNS

Unless you manage a large, complex network, chances are better than average that you'll work with someone else's DNS server - probably your ISP's - rather than managing your own. However, if you have a large network with more than 1000 computers, or if your network spans multiple sites using private wide-area links, a DNS server may be just the thing to help you stake out the right type of Internet presence.

One unique feature of Windows 2003 is that it automatically installs three services on the first server of a domain: Active Directory, DHCP, and DNS. Although you don't actually have to employ DHCP and DNS, they're still installed by default. Installing these services is therefore a breeze (so much so that the Configure Your Server Wizard does it for you automatically). The real headaches come when you try to configure DNS (or DHCP for that matter).

The deans of DNS

If you think you may be interested in setting up a DNS server, you need to consult a technical resource, such as the Windows Server 2003 Resource Kit or TechNet. We also highly recommend DNS on Windows 2000 , a book by Matt Larson and Cricket Liu (published by O'Reilly & Associates) as the ultimate resource for using Windows 2000 as a DNS server. Even though the title says Windows 2000, this is also a great resource for Windows 2003 because DNS is almost exactly the same. Paul Albitz and Cricket Liu also wrote a general book called DNS and BIND , now in its fourth edition (also published by O'Reilly) that is widely regarded as the best general reference on DNS. Both of these books should be updated or revised soon to encompass new material for Windows Server 2003.

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Windows Server 2003 for Dummies
Windows Server 2003 for Dummies
ISBN: 0764516337
EAN: 2147483647
Year: 2003
Pages: 195

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