What is DNS
Dns helps to locate resources on the Internet and Intranet.It maps IP Adresses to domain names that are user-friendly.In a Windows Server environment DNS can be run as a individual service or be integrated in Active Directory.
Dns helps to locate resources on the Internet and Intranet.It maps IP Adresses to domain names that are user-friendly.In a Windows Server environment DNS can be run as a individual service or be integrated in Active Directory.
The DNS database holds various type of records.If you have a AD integrated DNS setup most of the records will be created automatically when adding resources to the domain,changing settings or promoting or denoting a domain controller.Each DNS Zone must have a start of authority record this is created when a zone is created for the first time and this record provide information for the zone such as primary server,refresh interval,retry interval, expires after,maximum time to live. A and AAAA records are used to map fully qualified domain name to an IP Adress. NS records are used to list authoritative DNS servers for the zone Mail exchanger records specify the MX server for a domain and that can be any mail server. Canonical name records are aliases for FDQN Srv records are used to specify the location of a service inside a infrastructure.In a AD enviroment these are important as they help to locate the nearest domain controller.
Microsoft DNS server supports four type of zones.
A Primary zone is a read and write container that contains the DNS records for the zone.There are two types of primary zones standard and AD-integrated.Standard primary zones are mostly used in non AD enviroments.The zone will be located in c:\windows\system32\DNS.In a AD integated primary zone the information is stored in Active Directory.Active Directory uses the multi-master replication method therefore we can update DNS records on any available domain controller and it will replicated to all other domain controllers.Primary zones are the only zone that can be edited.
A secondary zone keeps a read-only copy of the primary zone.It contacts the primary zone to get updates.This zone can not be stored in Active Directory.
Stub zone is a read-only copy of the master zone but contains only start of authority an name server records.Reverse lookup zones hold PTR records PTR records are used to map IP Adresses to FQDNs.
In DNS we use these to forward DNS queries to external DNS servers when it can not resole them internally.If the forwarders are not responding the DNS server will use Root Hints to resolve the query.
Queries between the server and client are normally in plain text format.Starting from Windows Server 2022 queries can pass through secure HTTP connections this setting is only for DNS clients and not for servers therfore you should not enable this setting domain joined computers.
There are two types of zone file replications.First one is Asynchronous Full Transfer Zone(AXFR).When you set up a new secondary zone the system will replicate a full copy of the zone from the master server.Second is the Incremental Zone Transfer(IXFR) after the initial full zone transfer,the system will only replicate the records that have been changed, this also reduces replication traffic.