Windows Server 2008 R2 by yantingting


									Windows Server
2008 R2
Domain Name System
Chapter 5
Domain Name System
•   Domain Name System (DNS) Terms
•   DNS components
•   Troubleshooting DNS
DNS Terms
• Hostname—name of the computer. No more than 255
  characters. Equivalent to the computers first name.
  • PC-001
• Host File—text file that lists hostnames to IP addresses
 • C:\windows\system32\drivers\etc
• Namespace—name of the domain, not specifically and Active
  Directory Domain. This is equivalent to the computers last
• Fully qualified domain name (FQDN)—first name and last
• Name server—DNS server that will resolve FQDN’s to IP
DNS Terms
• recursion—server directed process to resolve a FQDN. If the server
  cannot resolve it with it’s own information, it will ask an upstream
  server. The recursion process starts at the root servers for the .com
  and works down through the top level domain servers. The process is
  as follows:
  1.   Client requests a name like
  2.   DNS server asks the root servers for the .com domain name servers.
  3.   Root servers give a list of servers for the .com domain.
  4.   DNS servers query the .com nam servers for
  5.   It then queries the provided name servers for the FQDN
  6.   Finally, the DNS server provides the IP address
  7.   DNS server passes the IP address to the client.
  8.   The client uses the IP to connect to the web server for
DNS Terms
• Forwarding—alternative to recursion.
  Lateral request to another name server
  within the network.
• Service resource records (SRVs)—a
  record within a DNS namespace to
  resolve a service to a hostname.
  Essential to Active Directory.
• Dynamic DNS(DDNS) update—allows
  DNS client to register their hostnames
  in an assigned namespace.
DNS Components
• Fowarders—DNS servers to
  which the DNS server will
  refer queries when it cannot
  resolve them itself. Using
  forwarders prevents this
  server from using recursion
  to resolve DNS queries. You
  can use forwarders for
  quicker name resolution.
  Typically can configure to
  point to your ISP’s DNS
DNS Components
• Root Hints—servers to be used for root hints when forwarders
  are not configured or do not respond. Lists 13 root hint
  servers on the Internet. You can add your own servers.
DNS Components
• Forward Lookup Zones—resolves hostnames to IP addresses. Contains
  the host records for the configured zone. There are three types of zones:
   • Standard Primaryis a text file in which the server maintains the records for
     a given namespace.
   • Standard Secondaryread-only copy of primary or AD zone.
   • AD IntegratedDNS records are stored in the AD Database and replicated
     between DC’s, not zone transfers.
DNS Components
• Reverse Lookup Zone—resolves IP addresses to host names.
  Also used to provide a level of security with DNS reverse

                                                  lookup not

                                             Reverse lookup
DNS Components
• Service Resource/Locator Records (SRV)—contains Active Directory
  related information, such as authentication services.
  •   _gcLDAP service to look up data within the global catalog
  •   _kerberosThe authentication process
  •   _kpasswdanother part of authentication process
  •   _ldapLDAP service to look up data within the domain
DNS Troubleshooting
• Event loggingevent log created for the DNS role
• MonitoringMonitoring tab in DNS server properties which allows
  you to do simple pass/fail tests and recursive tests
• NSLookupcan query your own server or remotes domain names.
• DNScmdcommand-line tool that can perform most tasks in the
  GUI as well as troubleshooting tasks.
  • Dnscmd /infoconfiguration of the DNS server
  • Dnscmd /clearcache empties stale, unresolved records
• Net viewuses netBIOS to retrieve info about a host
• Nbtstatuses the netBIOS table to view information about a host or
  IP address.
• PINGtest connectivity by IP address AND by hostname.
• Dcdiagfirst choice to perform a quick health check on the DNS

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