Zones and SOA(state of Authority)

Key terms for this section include the following:

Term	Definition
Start of Authority (SOA) Records	A record in a DNS zone that is integrated into the zone properties dialog box that contains the name of the DNS server, the zone administrator and other key settings.
Stub Zones	A DNS zone that contains information used to directly forward queries to a specific external DNS zone.
GlobalNames Zones	A DNS zone used to resolve single label names in a domain to IP addresses.

Start of Authority (SOA) Records

The SOA record exists in a DNS zone, but is integrated into the Properties dialog box. The SOA contains:

• The name of the DNS server

• The zone administrator

• Key settings:

  • How often zone transfers occur

  • The wait time before failed zone transfers are retried

  • The time that data can be used on a secondary DNS server before it expires

  • The default time-to-live on resource records

Stub Zones

Stub Zones are often used when a child zone is located on a different DNS server. For example:

• One DNS server is authoritative for the CorpNet.xyz zone.

• Another DNS server is authoritative for east.CorpNet.xyz.

A stub zone:

• Contains a copy of selected records from the primary zone.

  • The SOA record.

  • Host records for the DNS servers in the primary zone.

  • Records that identify the servers as DSN servers.

• Behaves like a Conditional Forwarder.

  • Forwards queries to DNS server identified in the stub zone.

Stub zones can be created using the DNS Manager utility or with command prompt and PowerShell commands.

Utility	Steps or Commands
DNS Manager	Create the zone using the New Zone wizard. Choose Stub zone. Enter the IP address or FQDN of the Master DNS server where primary zone exists.
Command Prompt	C:\>dnscmd <DSN server> /zoneadd <name of zone> /stub <master DNS>
PowerShell	PS C:\>Add-DnsServerStubZone -Name <DSN server> -MasterServers <Master DNS> -PassThru -ZoneFile "<file name>"

GlobalNames Zones

The GlobalNames zone is used to resolve single label names in a domain for older Windows NT hosts and hosts supported by WINS.

Create a GlobalNames zone as follows:

1. Create a zone.

   1. Create the zone using the New Zone wizard.

   2. Choose Primary zone.

   3. Name it GlobalNames.

2. Enable GlobalNames from the command prompt as follows: C:\>dnscmd <DNS server> /config /enableglobalnamessupport 1