domain name system (dns)
DESCRIPTION
Domain Name System (DNS). Domain Name System (DNS). How DNS Works. Name Server. DNS Resolver. Application. Application. Sockets. Transport. Transport. Internet. Internet. Network. Network. COM. EDU. ORG. Domain Name Space. Root-Level Domain. Countries. Top-Level Domain. - PowerPoint PPT PresentationTRANSCRIPT
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Domain Name System (DNS)
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Domain Name System (DNS)
Green
Blue
Red
Yellow
Orange
Purple
SRI-NIC
Green 191.105.6.10
Blue 195.200.90.2
Red 202.131.6.200
Yellow 159.166.99.67
Orange 121.17.6.22
Purple 212.191.7.45
Hosts.txt
FTP Orange
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How DNS Works
ApplicationApplication
TransportTransport
InternetInternet
NetworkNetwork
ApplicationApplication
TransportTransport
InternetInternet
NetworkNetwork
DNS Resolver
Name Server
Sockets
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Domain Name Space
Root-Level Domain
New Zealand (NZ) COM EDU ORG
microsoft compaq purdue
StudentSeattle
Top-Level Domain
Second-Level Domain
Countries
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Zones of Authority
CORP
R&D
MKTG
com
Microsoft
Name Servers
Name Server
Name Server
Zone 1
Zone 3
Zone 2
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Name Server Roles
Primary Name Server
Zone information in locally maintained files
Secondary Name Server
Zone information downloaded from a master name server
Master Name Server
Source of information for a secondary server; can be a primary or secondary server
Caching Only
Does not keep any zone information
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Name Resolution
Local Name Server
RootName Server
govName Server
whitehouse.govName ServerDNS
Client
RecursiveQuery
IterativeQueries
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2233
44
5566
7788
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Inverse Queries
Special Domain for Inverse Queries
in-addr.arpa
IP Addresses Reversed when Converted to DNS Inverse Queries
157.55.200.51 becomes query for 51.200.55.157.in-addr.arpa
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Configuring the DNS Files
Database File (zone.dns)
Contains resource records for the zone
Typically maps host names to IP addresses
Reverse Lookup File (z.y.w.x.in-addr.arpa)
Maps IP addresses to host names
Cache File (cache.dns)
Names and addresses of root domain name servers
Boot File
Used by manual start-up method
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The Database File
Stores Resource Records
RFC 1034 CompliantSOA, A, NS, PTR, CNAME, MX, HINFO
Microsoft SpecificWINS, WINS-R
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The Reverse Lookup File
Supports inverse queries
For inverse queries for IP network 157.57.28.0, file name created:
db.57.157.in-addr.arpa
Example resource record entry:
51.200.55.157.in-addr.arpa. IN PTR mailsrv3.microsoft.com.51.200.55.157.in-addr.arpa. IN PTR mailsrv3.microsoft.com.
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Review
Domain Name System (DNS)
Name Resolution
Configuring the DNS Files
Planning a DNS Implementation