Learning Goals//The goal of this lesson is to provide students with in-depth knowledge of Domain Name Server (DNS) name resolution.
Upon completion of this lesson, students will understand:
DNS name resolution
Configuring additional services
Lesson Introduction
Explain that Microsoft Windows Server 2008 Active Directory uses DNS for name resolution and that this tool is used for de-ployment and administration of a functional Active Directory infrastructure. Students will learn about DNS Zones and deploy additional services within the Active Directory environment.DNS Name Resolution
Instructors should do the following: Explain that name resolution is an essential function on all Transmission Control Protocol/Internet Protocol (TCP/IP) networks.
Point out that the network administrator will determine computer names at the time that the network is set up.
Explain that DNS is the name resolution mechanism com-puters use for all Internet communication and is primarily used in Active Directory.
Point out that one method of resolving names is to use a host file.
Explain that the host table in the host files consists of the IP address, host name, and comments.
Discuss how DNS maintains an extensive list of IP addresses and hosts through a distributed database.
Point out that DNS consists of the following three elements:
DNS namespace
Name servers
Resolvers
Explain that the DNS name resolution process consists of a resolver submitting a name resolution request to its desig-nated DNS server.
Explain that a DNS domain is an administrative entity that consists of a group of hosts, usually a combination of com-puters, routers, printers, and other TCP/IP-enabled devices.
Point out that the following are DNS configuration items:
Resource records
Start of Authority (SOA)
Name Server (NS)
Host (A)
Host (AAA)
Canonical Name (CNAME)
Host Information (HINFO)
Mail Exchanger (MX)
Pointer (PTR)
Service Record (SRV)
Explain that the hierarchy levels of the DNS domain namespace make it possible to locate an authoritative source for any domain name.
Point out that root name servers are at the top of the do-main hierarchy.
Explain that other top-level domains include:
Com
Explain that to create authoritative sources for your Inter-net domain, the administrator can deploy the organization’s own DNS servers.
Discuss the process of DNS name resolution on the Internet.
Point out that caching is a process that can speed up the DNS name resolution process.
Explain that a referral is the process where one DNS server sends a name resolution request to another DNS server.
Explain that the two types of name resolution requests are recursive query and iterative query.
Discuss the process of name resolution.
Explain that reverse name resolution is the process of con-verting an IP address into a DNS name.
Explain that since most organizations provide an internal network and external Internet presence, resources must be carefully managed to provide seamless access to resources.
Explain that the following strategies will help in managing internal and external domains:
Use the same domain name internally and externally (highly discouraged)
Create separate and unrelated internal and external domains
Make the internal domain a subdomain of the exter-nal domain
Explain that as the server performs client name resolutions, it builds up a cache of DNS information.
Point out that a DNS server that contains no zones and hosts no domains is a caching-only server.
Point out that a forwarder is a DNS server that receives que-ries from other DNS servers and is configured to forward them.
Explain that conditional forwarding is available in Windows Server 2008 to enable administrators to forward queries based upon the domain specified in the name resolution request.
Explain that a DNS zone is an administrative entity on the DNS server that represents a discrete portion of the DNS namespace.
Point out that zone types specify the servers that store the zone database and the information it contains:
Primary zone
Secondary zone
Stub zone
Point out that the administrator can configure standard DNS zones for the transfer from primary zones to secondary zones.
Demonstrate how to configure a standard DNS zone using Administrative Tools.
Explain that a full zone transfer is performed when a new DNS server is created on the network to obtain a full copy of all resource records for the zone.
Point out that Windows Server 2008 also supports incre-mental zone transfer (IXFR), which is a revised DNS zone transfer process for intermediate changes.
Explain that if Active Directory is run on the network, you must have at least one DNS server on the network that sup-ports the SRV resource record.
Point out that Active Directory conserves bandwidth by replicating only the DNS data that has changed since the last replication.
Explain that Windows Server 2008 replicates the database for a zone stored in Active Directory to all the other do-main controllers running the DNS service in the Active Di-rectory domain where the primary zone is located.
Demonstrate how to configure a custom application direc-tory partition at the Windows Command Prompt.
Explain that after DNS servers are configured, the client computers must be configured.
Demonstrate how to configure DNS client settings manual-ly using the Server Manager.
Demonstrate how to configure DNS/WINS Integration using Administrative Tools.