Monday, November 30, 2009

DNS Server

As read in my previous blog about Stub Zones, In this blog we will study more about different types of DNS Zones. In Windows 2003 Server we can find 4 types of DNS Zones. viz

a. Primary Zones : Primary Zones are a read/write copy and can be created on any Server with DNS component installed.

b. Secondary Zones : Secondary Zones can store read-only copy of the of the DNS server.

c. Active Directory Zones : Active Directory Integrated Zone is a secured read/write copy of DNS database that can only be created on Domain Controller, the DNS database is integrated with Active directory database i.e. ntds.dit, thus providing state of class encryption and security to DNS database which otherwise is vulnerable to attack consequently raising security concerns.

d. Stub Zones

In DNS ,replication is addressed as Zone Transfers, zone transfers happen in secure encrypted mode. In primary and secondary zone transfers ,the secondary copies the whole copy of the primary database. In Active Directory Integrated Zone the initial transfer is full transfer which is referred as AXPR and incremental which is referred as IXPR thereafter.

Some lesser known facts about DNS

· WINS is replacement for LMHOST, similarly DNS is replacement for HOST file.

· WinNT supports only primary and secondary DNS database, Windows NT is a static DNS,where as Windows 2000 and 2003 support Dynamic DNS.

· AD and DNS are mutually dependent ,AD needs DNS for name resolution and DNS needs AD for security.