Dns

DNSDomain Name Service/Domain Name System

DNS in Microsoft Windows Server 2003

What is DNS?

- Domain Name Service/Domain Name System - Provides resolution of names to IP addresses and resolution of IP addresses to names - Defines a hierarchical namespace where each level of the namespace is separated by a “.”What is a DNS Server?- Computer running DNS serviceCan be: - Microsoft® Windows® Server 2003 - Windows 2000 - Microsoft Windows® NT 4 - UNIX - Linux - NetWare Etc. How Names Are Mapped to IP Addresses

DNS Namespace

Query TypesRecursive QueriesA query made from a client to a DNS server in which the server assumes full workload. DNS server returns either a complete answer or negative answer.Iterative QueriesReceiving server may return an answer, a negative response, or a referral to other DNS Server's “Give me an answer or refer me to somebody else who can help me obtain resolution.” Issued by: DNS Servers

Lookup Types : Forward lookupRequests Name-to-IP Address resolution

Reverse lookupRequests IP Address-to-Name resolution

Fully Qualified Domain Name (FQDN) Identifies a host’s name within the DNS namespace hierarchy Host name plus DNS domain name = FQDN

ZONE:Zone is a storage database which contains all zone RecordsForward Lookup Zone - Used for Resolving Host Names to IP-Address - It maintains Host to IP Address Mapping InformationReverse Lookup Zone - Used for Resolving IP-Address to Host Names - It maintains IP Address to Host Mapping InformationTypes of Records1-SOA Record The first record in any zone file2-N S Record Identifies the DNS server for each zone3-Host Record Resolves a host name to an IP address4-Alias Record Resolves an alias name to a host name

Zone Types:1-Standard PrimaryIt is the Master Copy of all the Zone Information.It is Read/Write copy2- Standard SecondaryIt is Backup to Primary zone. It is Read Only3-Stub ZoneIt contains only NS ,SOA & possibly Glue (A) Recordswhich are used to locate name servers

Active Directory IntegratedIt stores the information of Zone in ACTIVE DIRECTORYDATABASE

How can installing DNS:-

Requirement - DC member server or workgroup - Static IP Address 7-10-1-How to install DNS?

start -> setting -> control panel

add and remove program ->

add and remove windows component

select network service -> details

check the box on [ √ ] D omain N ame S ystem (DNS) -> ok -> next

ok -> finish to Access DNS start -> program ->administrative tools -> DNS or -> start -> run -> [ dnsmgmt.msc]

create Zone -> start -> program ->administrative tools -> DNS -> expand server name-> expand forward lookup zone -> right click forward lookup zone -> new zone -> next

select primary zone -> next

select To all DNS server in the active Directory domain (domain name ) -> next

give the zone name eg : ( yahoo.com ) -> next

select allow both nonsecure and secure dynamic update -> next

finish

Create Host record right click on zone (yahoo.com ) -> new host

give the system name> and IP address -> click on add Host -> done

right click on zone (yahoo.com ) -> new Alias (CNAME)

give the alias name (www) ->

click browse -> double click on (system name ) -> double click on (forward lookup zone ) ) -> double click on (zone name “yahoo.com”) -> select host name -> ok ->

to check the resolution

start -> run -> [cmd ] -> ping [ www.yahoo.com]

Note : suppose the resolution is not showing Type command [ c:\ ipconfig /flushdns ]

Secondary zone

DC member server (anther DNS server)ip add 192.168.1.1 192.168.1.2DNS 192.168.1.1 192.168.1.1On DC : -> Create primary zone Eg www.yahoo.com On member server : create secondary zone with same name ( www.yahoo.com) start -> program ->administrative tools -> DNS -> expand server name-> expand forward lookup zone -> right click forward lookup zone -> new zone -> next

select secondary zone -> next

give the zone name -> next

assign the IP Address of first DNS server ( 192.168.0.1) -> next -> finish

right click on primary zone -> proprieties -> select zone transfer

ON the DC

->check the box [√] allow zone transfer -> select only to the following server -> assign the IP address of the DNS of member server -> apply -> ok

ON member server right click on secondary zone -> select transfer from master refresh

create sub zone

DC member server (anther DNS server)ip add 192.168.1.1 192.168.1.2DNS 192.168.1.1 192.168.1.1

-> On DC : -> Create primary zone Eg www.yahoo.com -> On member server : create secondary zone with same name ( www.yahoo.com) start -> program ->administrative tools -> DNS -> expand server name-> expand forward lookup zone -> right click forward lookup zone -> new zone -> next

select sub zone -> next -> next

give the sub zone name

->assign the DNS (primary) IP Address

next -> finish Note : to see the information present in cache [C:\ ipconfig /displaydns ]

To remove the information in cache [ c:\ ipconfig /flushdns ]

Reverse lookup zone create primary zone on forward lookup zone with host and alias create reverse lookup zone right click on reverse lookup zone -> new zone -> next

select primary zone -> next

next assign the network ID -> next

select [ allow both non secure & secure dynamic update ]

-> next -> finish

Create Pointer : right click on reverse lookup zone -> new pointer (PTR)

assign the Host IP -> click on Browse -> select

-> double click on (system name ) -> double click on (forward lookup zone ) ) -> double click on (zone name “yahoo.com”) -> select host name -> ok -> ok

To check the reverse lookup zone open cmd type [ c:\ NSLOOKUP “ IP ADDRESS ” ]

Forwarders Forwarders in DNS server configure forwarder so that it can forwarded the query to anther . DNS server where it can complete the resolution .You can also configure forwarders for load balancing .To configure forwarder -> check the IP address for tow different DNS server

ON SYS1 create zone with host record and alias name (www.yahoo.com ) ON SYS2

Sys1 Sys2

IP 192.168.0.1

DNS 192.168.0.1IP 192.168.0.2

DNS 192.168.0.2

create zone with host record and alias name (www.google.com ) ON SYS1 open cmd ping www.yahoo.com reply and ping www.google.com not

reply open DNS right system name -> properties -> forwarder and assign the IP

address of DNS ( SYS2) -> apply -> ok open cmd ping www.google.com reply

Internet Information Service ( IIS )