Microsoft® Official Course
 Module 7
Implementing Domain NameSystem
Module Overview
•Name Resolution for Windows Clients and ServersInstalling and Managing a DNS ServerManaging DNS Zones
Lesson 1: Name Resolution for Windows Clientsand Servers
•What Are Computer Names?What Is DNS?DNS Zones and RecordsHow Internet DNS Names Are ResolvedWhat Is LinkLocal Multicast Name Resolution?How a Client Resolves a NameTroubleshooting Name Resolution
What Are Computer Names?
Computer_DesktopComputer01
Computer_DesktopComputer01
host computer
Name
Description
Host name
•Up to 255 characters long
•Can contain alphabetic and numericcharacters, periods, and hyphens
•Part of FQDN
NetBIOS name
•Represent a single computer orgroup of computers
•15 characters used for the name
•16th character identifies service
•Flat namespace
What Is DNS?
DNS can be used to:
•Resolve host names to IP addresses
•Locate domain controllers and global catalogservers
•Resolve IP addresses to host names
•Locate mail servers during email delivery
DNS Zones and Records
A DNS zone is a specific portion of DNS namespacethat contains DNS records
Zone types:
•Forward lookup zone
•Reverse lookup zone
Resource records in forward lookup zonesinclude:
•A, MX, SRV, NS, SOA, and CNAME
Resource records in reverse lookup zones include:
•PTR
How Internet DNS Names Are Resolved
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Workstation
IP address This is the 8th of 8 frames. The IP address of the microsoft.com DNS server appears beside the workstation.
207.46.230.219
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Local DNS server
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This is the 1st of 8 frames on a build slide. It shows a workstation, a local DNS server, a root DNS server, a .com DNS server, and a Microsoft.com DNS server. The workstation has a query for the IP address of www.microsoft.com.
What is the IP addressofwww.microsoft.com?
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Root DNS server
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.com DNS server
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Microsoft.com DNS server
This is the 2nd of 8 frames. The workstation sends the query for the IP address to the local DNS server. This is represented by an arrow that appears pointing from the workstation to the server.
This is the 3rd of 8 frames. The local DNS server does not have the IP address in its cache so it sends the query to the root DNS server. This is represented by an arrow that appears pointing from the local server to the root server.
This is the 7th of 8 frames. The local DNS server provides the IP address of www.microsoft.com to the workstation client. This is represented by an arrow that appears pointing from the local server to the workstation.
This is the 6th of 8 frames. The DNS server that hosts the microsoft.com domain returns the IP address of www.microsoft.com to the local DNS server. This is represented by an arrow that appears pointing from the microsoft.com server to the local server.
This is the 4th of 8 frames. The root DNS server did not have the IP address so the local DNS server sends the query to the .com DNS server. This is represented by an arrow that appears pointing from the local server to the .com server.
This is the 5th of 8 frames. The .com DNS server finds the IP address and directs the local DNS server to the microsoft.com DNS server. This is represented by an arrow that appears pointing from the local server to the microsoft.com server.
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What Is LinkLocal Multicast Name Resolution?
LLMNR is an additional method for nameresolution that does not use DNS or WINS
•LLMNR is designed for IPv6
•Works only on Windows Vista, Windows Server2008, and all newer Windows operating systems
•Network Discovery must be enabled
•Can be controlled via Group Policy
How a Client Resolves a Name
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5. NetBIOS Name Cache
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6. WINSServer
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7. Broadcast
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2. DNSResolverCache /Hosts filecontent
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1. Local Host Name
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8. Lmhosts File
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3. DNSServer
4. LLMNR
Troubleshooting Name Resolution
Common tools for troubleshooting name resolutionare:
•Consider using the new cmdlets in WindowsPowerShell to manage and troubleshoot DNS
•Always clear DNS resolver cache beforetroubleshooting
•Use the hosts file for troubleshooting
•Isolate problem
•Nslookup
•Dnscmd
•Dnslint
•Ipconfig
•DNS Server Monitoring
Lesson 2: Installing and Managing a DNS Server
•What Are the Components of a DNS Solution?What Are Root Hints?What Are DNS Queries?What Is Forwarding?How DNS Server Caching WorksHow to Install the DNS Server RoleDemonstration: Installing the DNS Server Role
What Are the Components of a DNS Solution?
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DNS Servers onthe Internet
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DNSServers
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DNSResolvers
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Resource
Record
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Root “.”
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.com
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.edu
The slide has 3 sets of graphics which are connected with dotted lines which represent lines of communication. From the left the sets of graphics are: 1. DNS resolvers 2. DNS servers and resource records 3. DNS servers on the Internet with databases. The databases include root (abbreviated simply as dot), .com, and .edu.
Resource
Record
What Are Root Hints?
microsoft
DNSServers
DNSServer
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com
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Client
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RootHints
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Root (.) Servers
Root hints contain the IP addresses forDNS root servers
What Are DNS Queries?
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DNS client
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mail1.contoso.com
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172.16.64.11
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A recursive query is sent to a DNS server and requiresa complete answer
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Database
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Local DNS server
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An iterative query directed to a DNS server may beanswered with a referral to another DNS server
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client
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Local DNS server
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Root hint (.)
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.com
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Recursive query
mail1.contoso.com
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172.16.64.11
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Iterative query
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Iterative query
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Iterative query
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Ask .com
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Ask contoso.com
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Authoritative response
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contoso.com
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•Queries are recursive or iterative
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•DNS clients and DNS servers initiate queries
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•DNS servers are authoritative or nonauthoritative for anamespace
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•An authoritative DNS server for the namespace willeither:
•Return the requested IP address
•Return an authoritative “No”
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•A nonauthoritative DNS server for the namespace willeither:
•Check its cache
•Use forwarders
•Use root hints
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What Is Forwarding?
A forwarder is a DNS
A forwarder is a DNS
A forwarder is a DNS
A forwarder is a DNS
ISP DNS
A forwarder is a DNS
A forwarder is a DNS
All other DNS domains
A forwarder is a DNS
Local DNS
contoso.com DNS
contoso.com
A forwarder is a DNS
A forwarder is a DNS
Query for
www.contoso.com
Conditional forwarding forwards requests using a domainname condition
Clientcomputer
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A forwarder is a DNS
A forwarder is a DNS server designated to resolve external oroffsite DNS domain names
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contoso.com
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Root hint (.)
.com
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Iterative query
Iterative query
Iterative query
Ask .com
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Ask contoso.com
Authoritative response
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Forwarder
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Recursive query for
mail1.contoso.com
131.107.0.11
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131.107.0.11
Recursive query
Local DNS server
client
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This is the 2nd of 3 frames. Client 1 sends a query for the IP address of Server A. The request and resolution is a multi-step process because the local server must query other DNS servers for the address. These multiple steps are represented by arrows pointing from Client 1, to the local server, and on out to the external servers. Once Server A is found arrows point from it to the external servers, to the local server, and so back to Client 1.
Where’sServerA?
ServerA is at131.107.0.44
This is the 3rd of 3 frames. Client 1 sends a query for the IP address of Server A. This request and resolution is a short 2 step process because the local server has the address in its cache. The 2 steps are represented by 2 arrows between Client 2 and the local server.
Where’sServerA?
ServerA is at131.107.0.44
How DNS Server Caching Works
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This is the 1st of 3 frames on a build slide. It shows 2 clients, a local server, and a number of external servers (one of the external servers is Server A). There are no moving graphics on this frame.
Client1
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Client2
ServerA
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DNS server cache
Host name
IP address
TTL
ServerA.contoso.com
131.107.0.44
28 seconds
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How to Install the DNS Server Role
DNS Server Installation Methods
•Server Manager
•Active Directory Domain Services Installation Wizard
Tools available to manage DNS Server
•DNS Manager Snap-In
•Server Manager
•DNS Manager console (dnsmgmt.msc)
•DNSCmd command-line tool
•Windows Powershell
•Remote Server Administrative tools
Demonstration: Installing the DNS Server Role
In this demonstration, you will see how to:
•Install a second DNS server
•Configure forwarding
Lesson 3: Managing DNS Zones
•What Are DNS Zone Types?What Are Dynamic Updates?What Are Active Directory–Integrated Zones?Demonstration: Creating an Active Directory–Integrated Zone
What Are DNS Zone Types?
Zones
Description
Primary
Read/write copy of a DNSdatabase
Secondary
Read-only copy of a DNS database
Stub
Copy of a zone that contains onlyrecords used to locate nameservers
ActiveDirectory–integrated
Zone data is stored in AD DS ratherthan in zone files
What Are Dynamic Updates?
1.Client sends SOA query
2.DNS server returns SOA resource record
3.Client sends dynamic update request(s) to identify theprimary DNS server
4.DNS server responds that it can perform update
5.Client sends unsecuredupdate to DNS server
6.If zone permits onlysecure updates, update isrefused
7.Client sends securedupdate to DNS server
ResourceRecords
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DNSServer
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What Are Active Directory–Integrated Zones?
Benefits of an Active Directory–integrated zone include:
•Allows multimaster writes to zone
•Replicates DNS zone information by using AD DSreplication
•Leverages efficient replication topology
•Uses efficient incremental updates for Active Directoryreplication processes
•Enables secure dynamic updates
•Security: Can delegate zones, domains, resource records
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Demonstration: Creating an Active Directory–Integrated Zone
In this demonstration, you will see how to:
•Promote a server as a domain controller
•Create an Active Directory–integrated zone
•Create a record
•Verify replication to a second DNS server
Lab: Implementing DNS
•Exercise 1: Installing and Configuring DNSExercise 2: Creating Host Records in DNSExercise 3: Managing the DNS Server Cache
Logon Information
Virtual machines20410B‑LON‑DC1
20410B‑LON‑SVR1
20410B‑LON‑CL1
User nameAdatum\Administrator
PasswordPa$$w0rd
Estimated Time: 40 minutes
Lab Scenario
A. Datum Corporation has an IT office and data center inLondon, which supports the London location and otherlocations. A. Datum has recently deployed a Windows2012 Server infrastructure with Windows 8 clients. Youneed to configure the infrastructure service for a newbranch office.
Your manager has asked you to configure the domaincontroller in the branch office as a DNS server. You havealso been asked to create some new host records tosupport a new application that is being installed. Finally,you need to configure forwarding on the DNS server in thebranch office to support Internet name resolution.
Lab Review
•Can you install the DNS server role on a serverthat is not a domain controller? If yes, are thereany limitations?What is the most common way to carry outInternet name resolution on a local DNS?How can you browse the content of the DNSresolver cache on a DNS server?
Module Review and Takeaways
•Review QuestionsToolsBest PracticeCommon Issues and Troubleshooting Tips