8/14/2019 Basic DNS

1/24

8/14/2019 Basic DNS

2/24

2

OverviewOverview

DNS ReviewDNS Review

Domain NamespaceDomain Namespace

ZonesZones DNS FilesDNS Files

Resource RecordsResource Records

8/14/2019 Basic DNS

3/24

3

Original name resolution throughOriginal name resolution through HOSTS.TXT FileHOSTS.TXT File

Flat name spaceFlat name space DNS Design GoalsDNS Design Goals

Hierarchical name spaceHierarchical name space

Distribution of data and administrationDistribution of data and administration

Extensible data typesExtensible data types Unlimited database sizeUnlimited database size

DNS ReviewDNS Review

8/14/2019 Basic DNS

4/24

4

Domain Name SpaceDomain Name Space

com mil org

navywhitehouse

gov

microsoft

acme

supportdevrhino

Managed by InterNIC

Microsoft Domain -

Managed by Microsoft

edu

uw mit

8/14/2019 Basic DNS

5/24

5

ZonesZones

microsoft

ftpdev

comorg

mil

microsoft.com.

zone

microsoft.com.

domain

dev.microsoft.com.

zone

8/14/2019 Basic DNS

6/24

6

DNS FilesDNS Files

Zone Database FilesZone Database Files

Cache FileCache File

Reverse Lookup FilesReverse Lookup Files

Boot FileBoot File DNS Manager can now be used with bootDNS Manager can now be used with boot

filefile

8/14/2019 Basic DNS

7/24

8/14/2019 Basic DNS

8/24

8

Dynamic Domain Name System (DDNS)Dynamic Domain Name System (DDNS)

DNS for Windows 2000 ServerDNS for Windows 2000 Server SRV resource recordsSRV resource records

Naming specificationNaming specification

Name resolutionName resolution

Installation & configurationInstallation & configuration

Zone transfers (AXFR & IXFR)Zone transfers (AXFR & IXFR)

Services integrationServices integration

Dynamic updateDynamic update

8/14/2019 Basic DNS

9/24

9

Domain Controller (SRV) RecordsDomain Controller (SRV) Records

Finding a domainFinding a domaincontrollercontroller

SRV recordsSRV records The MS-DCS domainThe MS-DCS domain

namename Locating specificLocating specific

serversservers

A recordsA records

CNAME recordsCNAME records

Local

Name

Server

DomainController

DNS Client

Query to local name

server forldap.tcp.nt.microsoft

.com.

8/14/2019 Basic DNS

10/24

10

Windows 2000 DNS NamingWindows 2000 DNS NamingSpecificationsSpecifications

Naming StandardsNaming Standards RFC 1123 standardsRFC 1123 standards UnicodeUnicode support for non-ASCII charactersupport for non-ASCII character

setssets

Domain NamesDomain Names Primary DNS domainPrimary DNS domain Possible to have one domain name perPossible to have one domain name per

adapteradapter

Host NamesHost Names May have multiple FQDNsMay have multiple FQDNs Same as NetBIOS nameSame as NetBIOS name

8/14/2019 Basic DNS

11/24

11

Client Name ResolutionClient Name Resolution

Multiple Fully Qualified Domain NamesMultiple Fully Qualified Domain Names Primary DNS domain namePrimary DNS domain name

Adapter DNS domain nameAdapter DNS domain name

Four different names possible in a queryFour different names possible in a query NullNull

Fully qualifiedFully qualified

Unqualified single-labelUnqualified single-label

Unqualified multi-labelUnqualified multi-label

Client caches query resultsClient caches query results

8/14/2019 Basic DNS

12/24

12

Name Resolution QueriesName Resolution Queries

whitehouse

gov

www

Root

NameServer

gov

NameServer

whitehouse.gov

Name Server

DNS Client

Recursive

Query

Iterative

Queries

1

2 3

4

5

678

8/14/2019 Basic DNS

13/24

13

Installing Microsoft Windows 2000 DNS ServiceInstalling Microsoft Windows 2000 DNS Service

Installation ProcessInstallation Process \\%systemroot%%systemroot%\system32\DNS directory\system32\DNS directory

created for Zone file storagecreated for Zone file storage

\HKLM\System\CurrentControlSet\Services\DNS\HKLM\System\CurrentControlSet\Services\DNSregistry key addedregistry key added

DNS ManagerDNS Manager now MMC Snap-innow MMC Snap-in Root Server creates default in-addrRoot Server creates default in-addr

zoneszones

0.in-addr.arpa0.in-addr.arpa 127.in.addr.arpa127.in.addr.arpa

255.in-addr.arpa255.in-addr.arpa

Cached lookups can be displayedCached lookups can be displayed

8/14/2019 Basic DNS

14/24

14

Customizing Microsoft Windows 2000 DNS ServiceCustomizing Microsoft Windows 2000 DNS Service

InterfacesInterfaces AdvancedAdvanced

Disable RecursionDisable Recursion

Bind SecondariesBind Secondaries Fail On Load If Bad Zone DataFail On Load If Bad Zone Data

Enable Round RobinEnable Round Robin

Enable Netmask OrderingEnable Netmask Ordering

Name CheckingName Checking Boot MethodBoot Method

Statistics, Logging, and MonitoringStatistics, Logging, and Monitoring

8/14/2019 Basic DNS

15/24

15

Setting Up Zones and DomainsSetting Up Zones and Domains

Configuring reverse lookup zonesConfiguring reverse lookup zones

Configuring forward lookup zonesConfiguring forward lookup zones

Adding subdomains to the zoneAdding subdomains to the zone

Adding host records to the zoneAdding host records to the zone

8/14/2019 Basic DNS

16/24

16

Zone TransfersZone Transfers

Full Zone TransfersFull Zone Transfers Copy entire zone to secondary serverCopy entire zone to secondary server

Incremental Zone TransfersIncremental Zone Transfers

Copy only changes to secondary serverCopy only changes to secondary serverbased upon cached historybased upon cached history

Must be supported at master andMust be supported at master andsecondary serverssecondary servers

DNS NotifyDNS Notify

8/14/2019 Basic DNS

17/24

17

Dynamic DNSDynamic DNS

Local

NameServer

DNS Dynamic

Update Client Source: 157.57.64.198Destination: 157.57.70.10

UPDATE:

hostb.nt.microsoft.com. IN A157.57.64.198

PREREQUISITES:Name is not in use:

hostb.nt.microsoft.com.

DynamicUPDATErequest

8/14/2019 Basic DNS

18/24

18

Secure Dynamic DNS UpdatesSecure Dynamic DNS Updates

Zones may be configured to useZones may be configured to useSecure Updates.Secure Updates.

Allows specified computers, users,Allows specified computers, users,and groups to add or modify zoneand groups to add or modify zoneentries.entries.

Secure Updates must be enabled inSecure Updates must be enabled inthe Active Directorythe Active Directory..

Modify specific containers as needed:Modify specific containers as needed: DnsZone ContainerDnsZone Container DnsDomain ContainerDnsDomain Container

8/14/2019 Basic DNS

19/24

19

Services Integration with Dynamic DNSServices Integration with Dynamic DNS

DNS

Service

WINS

Service

DHCP

Service

Active Directory

Service

8/14/2019 Basic DNS

20/24

8/14/2019 Basic DNS

21/24

21

DHCP IntegrationDHCP Integration

FQDN Option (DHCP Option 81).FQDN Option (DHCP Option 81). Clients can register A and have DHCPClients can register A and have DHCP

register PTR.register PTR. DHCP registers both A and PTR record.DHCP registers both A and PTR record. Client can request to register A, but DHCPClient can request to register A, but DHCP

overrides request and registers both A andoverrides request and registers both A andPTR records.PTR records.

Microsoft clients will register A and haveMicrosoft clients will register A and haveDHCP register PTR.DHCP register PTR.

DHCP is configurable to clean up ADHCP is configurable to clean up Aand PTR records upon lease expiration.and PTR records upon lease expiration. DHCP is configurable to register A andDHCP is configurable to register A and

PTR for legacy clients.PTR for legacy clients.

8/14/2019 Basic DNS

22/24

22

Active Directory Service IntegrationActive Directory Service Integration

BenefitsBenefits Single name space and replicationSingle name space and replicationtopologytopology

Multi-master replicationMulti-master replication

DNS Storage in the ADSDNS Storage in the ADS System container at the root of the NTSystem container at the root of the NTdomaindomain

Administrator access by defaultAdministrator access by default SecuritySecurity

DNS Server Operations and the ActiveDNS Server Operations and the ActiveDirectoryDirectory Primary, master, and secondary serversPrimary, master, and secondary servers Client registrationsClient registrations

8/14/2019 Basic DNS

23/24

23

ReviewReview

DNS reviewDNS review Domain controller recordsDomain controller records

Naming specificationsNaming specifications

Client name resolutionClient name resolution InstallationInstallation

Zone transfersZone transfers

Dynamic DNSDynamic DNS Services integrationServices integration

8/14/2019 Basic DNS

24/24

24