Types of DNS Server

Types of DNS Server

1. Primary               DNS              Server

2. Secondary           DNS              Server

3. Forward              DNS              Server

4. Cache                 DNS              Server

5. Root                            DNS              Server

1. Primary DNS Server

          It maintain primary DNS server it maintain master copy of the data base file if  any changes  of the data base file if any changes required in the zone file modification is possible only on primary server or it is a server which posting a primary zone.

2. Secondary DNS Server

          It is store copy of the data base in the zone file with the help of primary server. Secondary server is read only copy of the data base modification is not possible.

3. Forward DNS Server

          It is a external DNS server which required in case of resolving external DNS server

4. Cache DNS Server

          This type of DNS server does not store any zone file, it just resolve name to IP for client computer based on cache memory. It holds resent resolved information.

5. Root Server

          It is a server which posting root zone a company create its own root server if it has to maintain its own internal horirical structure.

Record Types of DNS

Host A Record:

          It is used to resolve name to IP address in the DNS server it is also called as forward lookup zone

PTR Record:

          It is used to resolve IP to name available in the reverse lookup zone

Aiase Record:

          If you required multiple name with same IP create a aliase record it is used for in website launching.

SOA Record:

          If you create a any zone. SOA record created automatically in the DNS server it holds information related to serial number, refresh interval, retry interval, expire record, TTL record

Serial Number Record:

          It is required to transfer the information from primary to secondary if any changes in the primary server using the serial number it modifies secondary server

Refresh Interval Record:

          If any modification in the primary server it takes 15 minutes  to copy to information to the secondary server.

Retry Interval Record:

          It is the amount of time, it wait for the primary server information to update the copy of the secondary server default it takes 20 minutes to wait for the primary

Expire After Record:

          Whenever secondary server successfully update the  quaries but refreshing is not possible on the secondary server it consider the time of the zone    is expire. Stop responding to the client quaries.

Time to Leave Record or TTL

          This type specify length of but time hold the server record information in the cache memory default all the resolved information available upto 1 hour in cache memory.

NS Record

          Name server record it indicates where DNS server is installed and record of DNS server

Mail Exchange Record

          It is used to send mails to the server using MEX record

Service Record or SRV

          It is available in DC and DNS server because it supports multimaster replication require session layer protocol to maintain the replication

How to configure DNS server

v      Click on  start button

v      Go to setting

v      Select control panel

v      In control panel select Add/Remove programme

v      Click on windows components

v      Select network services

v      Check domain name system (DNS)

How to create forward lookup zone

v      Right click on forward lookup zone

v      Select new zone

v      Click on next

v      Select primary zone

v      Select to all domain controller ion the

v      Click on next

v      Type zone name

v      Click on next

v      Select  second option

v      Click on next

v      Finish

To configure Host (A) record

v      Right click on zone name

v      Select new host

v      Type host name (www)

v      Assign the IP address

v      Select the add host

v      Ok and done

How to configure reverse look up zone

v      Right click on reverse lookup zone

v      Select new

v      Click on next

v      Select primary

v      Select third option

v      Click on next à type network ID

v      Click on next

v      Finish

v      Expand reverse look up zone

v      Right click on N/w ID

v      Select  new pointer à type host IP

v      Select browse

v      Select computer name

v      Select forward lookup zone

v      Select zone

v      Select www host name

v      Ok

Active directory integrated zones

          If the zone information is stored in active directory in stead of in the local DNS server path it is known as active directory integrated zones.

Advantages

Automatic Replication

          The DNS information replicates to other DNS or PC as part of active directory replication.

Multiple Primary DNS Server

          Active directory database being read/write copy on all the domain controllers we can have multiple DNS server

Secured Dynamic Updates

          Dynamic updates is feature which allows the DNS clients. To automatically update the records. (name and ip address in DNS server)

         

          Started from windows 2000 O S onwards on behalf of pre  windows 2000 clients. The DHCP server can register their name and ip in the DNS server

          The 3 options performing dynamic updates are updates off as follows

None

          Indicates dynamic updates are not allowed

NONE SECURE AND SECURE:

          Indicates any clients to update

SECURE ONLY:

          Allows only active directory clients to update

The zone replications can be as follows

v      To all DNS server in the forest

v      To all the DNS server in domain

v      To all domain controllers in the domain