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DNS in a Small BusinessDNS in a Small BusinessServer 2000 EnvironmentServer 2000 Environment

Frank BrownFrank BrownSupport ProfessionalSupport ProfessionalSmall Business ServerSmall Business ServerMicrosoft CorporationMicrosoft Corporation

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Introduction to the Domain NameIntroduction to the Domain Name

SystemSystem Distributed hierarchical namespaceDistributed hierarchical namespace

Resolves IP addresses to a recognizable hostResolves IP addresses to a recognizable host

name (forward lookups)name (forward lookups) Resolves host names to IP addressesResolves host names to IP addresses

(reverse lookups)(reverse lookups)

Used to locate resources in a MicrosoftUsed to locate resources in a MicrosoftActive Directory DomainActive Directory Domain

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Name Resolution ProcessName Resolution Process

Contoso.local

com

nwtraders.com

us.nwtraders.com

23

4

5

6

7

1

8

9

Host 1Host 2

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Zones vs. DomainsZones vs. Domains

Domain - a single node in the DNSDomain - a single node in the DNSnamespace and all of its descendant nodesnamespace and all of its descendant nodes

Zone - the set of resource records that areZone - the set of resource records that areassigned to a particular name serverassigned to a particular name server

Contoso.com

Northamerica.Contoso.com Southamerica.Contoso.com

Domain

Contoso.com

Northamerica.Contoso.com Southamerica.Contoso.com

Zone

Zone Zone

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DNS ServersDNS Servers

Primary serverPrimary server

Secondary serverSecondary server

Master serverMaster server Caching-only serverCaching-only server

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DNS Zones and Lookup TypesDNS Zones and Lookup Types

Zone filesZone files Standard primaryStandard primary

Standard secondaryStandard secondary Active Directory integratedActive Directory integrated

Lookup typesLookup types Forward lookup zonesForward lookup zones

Reverse lookup zonesReverse lookup zones

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DNS Zone FilesDNS Zone Files

Domain_NameDomain_Name.dns.dns

z.y.x.wz.y.x.w.in-addr.arpa.in-addr.arpa

Cache.dnsCache.dns Boot.dnsBoot.dns

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Resource RecordsResource Records

Resource recordsResource records SOA start of authoritySOA start of authority

NS name serverNS name server

A hostA host MX Mail ExchangerMX Mail Exchanger

CNAME canonical name (alias)CNAME canonical name (alias)

SRV serviceSRV service

Resource record fieldsResource record fields IN A IN A

.. IN SRV .. IN SRV

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Resource Records Registered byResource Records Registered by

Windows 2000 DomainWindows 2000 DomainControllersControllers

_ldap.tcp._ldap.tcp.

_ldap.tcp.sites._ldap.tcp.sites.

_ldap.tcp.pdc.ms-dcs._ldap.tcp.pdc.ms-dcs.

_ldap.tcp.gc.ms-dcs._ldap.tcp.gc.ms-dcs.

_ldap.tcp..sites.gc.ms-dcs._ldap.tcp..sites.gc.ms-dcs.

_ldap.tcp..domains.ms-dcs._ldap.tcp..domains.ms-dcs.

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Zone TransfersZone Transfers

A zone transfer is initiated when:A zone transfer is initiated when: A primary DNS server sends notification of zoneA primary DNS server sends notification of zonechanges to the secondary server or serverschanges to the secondary server or servers

The secondary server queries a master DNSThe secondary server queries a master DNS

server for changes to the zone fileserver for changes to the zone file

DNSServer(Primary)

nwtraders

trainingsupport

Primary ZoneDatabase File

Secondary ZoneDatabase File

DNSServer(Secondary)

Zone 1

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New Features in Windows 2000New Features in Windows 2000

Implementation of DNSImplementation of DNS Service location for Active Directory - DNS isService location for Active Directory - DNS is

used as a means to locate services in anused as a means to locate services in anActive Directory-based domainActive Directory-based domain

Multimaster replication - allows DNS to takeMultimaster replication - allows DNS to takeadvantage of the multimaster replicationadvantage of the multimaster replicationfeature of ADfeature of AD

Support for dynamic updates - client recordsSupport for dynamic updates - client recordsare updated either directly or through DHCPare updated either directly or through DHCP

Supports incremental zone transfersSupports incremental zone transfers

Integration with WINS and DHCPIntegration with WINS and DHCP

Enhanced caching and negative cachingEnhanced caching and negative caching

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Active Directory Integrated ZonesActive Directory Integrated Zones

Active Directory integrated zone data is:Active Directory integrated zone data is: Stored as an Active Directory objectStored as an Active Directory object Replicated as part of domain replicationReplicated as part of domain replication

Active Directorycontoso.c

om

DNS Server

Active DirectoryIntegrated Zone

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Dynamic UpdateDynamic Update DNS dynamic update protocolDNS dynamic update protocol

Allows clients to automatically update DNS serversAllows clients to automatically update DNS servers Can be used in conjunction with DHCPCan be used in conjunction with DHCP

DNS Server

Request for IP addressRequest for IP address11

Assign IP addressAssign IP address

of 192.168.16.33of 192.168.16.33

2

Zone DatabaseZone Database

Computer1192.168.16.33

DHCPServer

Windows 2000Windows 2000

client updatesclient updates

forward resourceforward resourcerecord on DNSrecord on DNS

serverserver

DHCP updatesDHCP updates

reverse resource recordreverse resource record

for Windows 2000for Windows 2000

clients and bothclients and both

resource records forresource records for

other clientsother clients

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How to Install DNSHow to Install DNS

Installed during Small Business Server setupInstalled during Small Business Server setup

Added during the installation of ActiveAdded during the installation of Active

Directory (DCPromo)Directory (DCPromo) Through Add/Remove Programs applet inThrough Add/Remove Programs applet in

Control Panel (Windows Components,Control Panel (Windows Components,Networking Services)Networking Services)

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Configuration of DNS During andConfiguration of DNS During and

After SBS 2000 InstallationAfter SBS 2000 Installation Domain name considerationsDomain name considerations

Using the Internet Connection WizardUsing the Internet Connection Wizard

Adding forwardersAdding forwarders Configuring the DNS properties of the serverConfiguring the DNS properties of the server

network cardsnetwork cards

Integration with DHCPIntegration with DHCP

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Domain Name ConsiderationsDomain Name Considerations

If your company has separateinternal and external namespaces

ISP DNS

Internal Domain

Private Network

local.

Contoso.localContoso.local

...contoso.local

...

Cache.dns

If your company has the sameinternal and external namespaces

.

Internet Root Domain

org.

Private Network

com.

Contoso.comContoso.com

...

contoso.com

...

org.com.

edu.au.

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Using the Internet ConnectionUsing the Internet Connection

WizardWizard

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Adding ForwardersAdding Forwarders

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DNS Settings of the ServerDNS Settings of the Server

Network Card(s)Network Card(s)

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Advanced DNS Server ParametersAdvanced DNS Server Parameters

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Troubleshooting ToolsTroubleshooting Tools

PingPing ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS] [-r count]ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS] [-r count]

[-s count] [[-j host-list] | [-k host-list]] [-w timeout][-s count] [[-j host-list] | [-k host-list]] [-w timeout]destination-listdestination-list

IPconfigIPconfig ipconfig [/? | /all | /release [adapter] | /renew [adapter] |ipconfig [/? | /all | /release [adapter] | /renew [adapter] |

/flushdns | /registerdns | /showclassid adapter | /setclassid/flushdns | /registerdns | /showclassid adapter | /setclassidadapter [classidtoset] ]adapter [classidtoset] ]

NslookupNslookup

DNS event logDNS event log DNS trace log enabled through the logging tab onDNS trace log enabled through the logging tab on

the DNS serverthe DNS server DNS.logDNS.log

Saved in systemroot\System32\DNS folderSaved in systemroot\System32\DNS folder

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NslookupNslookup

Use Nslookup to verify that the informationUse Nslookup to verify that the informationcontained in resource records is correctcontained in resource records is correct

Nslookup has two modes:Nslookup has two modes: InteractiveInteractive

NoninteractiveNoninteractive

Syntax:Syntax:

Nslookup [option] [computer-to-find] [server]Nslookup [option] [computer-to-find] [server]

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Common DNS Issues in SBS 2000Common DNS Issues in SBS 2000

Microsoft Windows 2000 clients cannotMicrosoft Windows 2000 clients cannotlogonlogon

SBS clients cannot resolve external DNSSBS clients cannot resolve external DNSnamesnames

Server hangs at Preparing NetworkServer hangs at Preparing NetworkConnectionsConnections

Netlogon errors 5775, 5781Netlogon errors 5775, 5781 Mail delivery issues cannot send/receiveMail delivery issues cannot send/receive

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Best PracticesBest Practices

Use the Internet Connection WizardUse the Internet Connection Wizard

Use separate internal and external DNSUse separate internal and external DNS

namespace (i.e. contoso.local, contoso.com)namespace (i.e. contoso.local, contoso.com)

Configure all network cards to use the SBSConfigure all network cards to use the SBSDNS serverDNS server

Configure the DNS server as a forwarderConfigure the DNS server as a forwarder

Configure zones to accept dynamic updatesConfigure zones to accept dynamic updates

Delete the . folder if it exists to allowDelete the . folder if it exists to allowinternet name resolutioninternet name resolution

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ResourcesResources

Windows 2000 DNS overview:Windows 2000 DNS overview: http://www.microsoft.com/windows2000/techinfo/http://www.microsoft.com/windows2000/techinfo/

howitworks/communications/nameadrmgmt/dnsohowitworks/communications/nameadrmgmt/dnsover.aspver.asp

Windows 2000 DNS white paper:Windows 2000 DNS white paper: http://www.microsoft.com/windows2000/techinfo/http://www.microsoft.com/windows2000/techinfo/

howitworks/communications/nameadrmgmt/w2kdhowitworks/communications/nameadrmgmt/w2kdns.aspns.asp

RFCs 1034, 1035, 2782, 2136RFCs 1034, 1035, 2782, 2136

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Resources (2)Resources (2)

Knowledge Base articlesKnowledge Base articles Q260371 Troubleshooting Common ActiveQ260371 Troubleshooting Common Active

Directory Issues in Windows 2000Directory Issues in Windows 2000

Q272674 IP Address Configuration for WindowsQ272674 IP Address Configuration for Windows2000 Domain Controllers2000 Domain Controllers

Q300202 How to Configure DNS for InternetQ300202 How to Configure DNS for InternetAccessAccess

Q229840 DNS Servers Root Hints and ForwarderQ229840 DNS Servers Root Hints and ForwarderPages are UnavailablePages are Unavailable

Q247811 How Domain Controllers are Located inQ247811 How Domain Controllers are Located inWindows 2000Windows 2000

Q249868 Replacing Root Hints with theQ249868 Replacing Root Hints with the

Cache.DNS fileCache.DNS file

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