Practice Exams for Windows

Practice Exams for Windows

Thursday, 22 October 2015

70-411 Exam Cram - Configure network services and access

Configure DNS records

Configure DNS Records including A, AAAA, PTR, SOA, NS, SRV, CNAME and MX Records

  • A records map host names to IPv4 addresses
  • AAAA records map host names to IPv6 addresses
  • PTR records are used for reverse DNS lookups
  • SOA records host authoritative zone information
  • SRV records specific service locations. Many newer software applications use SRV records. Such as Exchange ActiveSync and Citrix Receiver
  • CNAME records are used for aliases
  • MX records are used to specify mail servers for a domain
  • A lower preference on MX records ensures that those servers are used first
  • SRV records have a priority associated with them, records with a lower priority are used first

Configure zone scavenging

  • Use the Set-DnsServerZoneAging cmdlet to configure scavenging on a DNS zone. The -NoRefreshInterval parameter is used to configure, after how much time, a record can be removed. The -RefreshInterval is the allowed time between updates

Configure record options, including Time to Live (TTL) and weight

  • The SOA Record contains the authoritative name server for a zone and the general zone properties, including:
    • Serial number - Used by secondary servers to determine if a zone has changed
    • Refresh interval - Used to determine at which interval a secondary server checks for updates
    • Retry interval - Used to determine how long a secondary server waits to retry after a failed zone transfer
    • Expires After - Determines how long a secondary server will respond to DNS queries if it is unable to update from the primary server
    • Minimum (default) TTL - The amount of time a secondary server uses a record before it is expired and discarded
    • TTL for this record - The TTL for the SOA record itself
  • Dnscmd can be used to modify these values

Configure round robin

  • Round-Robin DNS allows for load balancing by pointing the same FQDN to different IP addresses
  • DNS Round-Robin can only be used with A Records

Configure secure dynamic updates

  • When Dynamic Updates is configured to 'Secure only', only the computers that are members of the DNS domain can register themselves with the DNS server. The DNS server automatically rejects the requests from the computers that do not belong to the domain
  • When Dynamic Updates are configured, clients can register and dynamically update their resource records with a DNS server whenever changes occur

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