DNS and DHCP

DNS Zones
Storage unit of Domain names + IPs
Mostly forward but also reverse
Stored in File or AD
 File (C:\windows\system32\Domain.Dns)
  -Primary + 1 or more secondary
  -Only Primary is R/W
  -Secondary updated by Primary or other secondary
 AD-Integrated
  -Stored in AD
  -Replicated with other AD data incrementally
  -Secure dynamic Updates

Forwarders+Stubs
Forwarders
Root hints:Internet top-level servers
Conditional:Commonly accessed domain DNS server

Stub Zones
 -Contains Authoritative DNS server resource records
  *SOA, *NS, *A(Glue)
 -Receives updates

Cache Management+Resource Records
DNS Server cache
 -Prevents redundant lookups
 -Usually valid for 1 day
 -Clear

Common RR
 -A (host record for IPv4), AAAA(host record for IPv6)
 -PTR (pointer record for reverse lookup)
 -CNAME (alias)
 -MX
To display DNS cache on client machine - ipconfig /displaydns


Namespace  This is the name of a domain, not specifi cally an Active Directory domain though. It’s a logical set of hosts signifi ed by a name controlled by a set of name servers. This is
equivalent to a computer’s last name; they’re all part of the same family. For example, Bigfirm.com is the namespace for hosts in the Bigfi rm.com domain.

Recursion  This is a server-directed process to resolve an FQDN. If the server cannot resolve the FQDN with its own information, it will send the query to other name servers. The recursion process comprises root servers and domain name servers. Root servers are the top of the hierarchical naming structure. The root servers list the name servers that control the top-level domain names such as .com, .gov, and .edu. The top-level domain servers control the registry of subdomains beneath the top-level domain.

Delegation  This means allowing another name server to control a subdomain of a given namespace. For example, the Bigfirm.com name servers can delegate control of the Ecoast.Bigfi rm.com namespace to another server.

Forwarding  This is an alternative to the recursion process. Forwarding is a lateral request to another name server within the network. The forwarding server obtains a response and relays it to the originating name server.

Iteration  This is a client-directed process to resolve an FQDN. If the client receives a negative request from a name server, it will query another name server.
NetBIOS Naming System  This legacy naming system was used primarily within old Microsoft NT 4.0 networks. Its processes are still part of modern-day Windows operating systems, however, particularly when using non-domain (workgroup)–based computers.

Service Records  Service records (SRVs) are records within a DNS namespace to resolve a service to a hostname. This is an essential part of DNS supporting Active Directory.

Dynamic DNS Update  Dynamic DNS (DDNS) update is a process that allows DNS clients to register their hostnames in an assigned namespace such as DHCP. This reduces the need of admins to manually enter records in the name server databases. This is another essential part of DNS supporting Active Directory.

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DHCP Process (DORA) - Discovery,Offer,Request,Acknowledge

DHCP Database

 -Backup

 -Restore

 -Reconcile

DHCP Failover

 -Load sharing

 -Hot standby