Delegate Subdomain to a Different DNS Server in Azure

A

You need to create a name server (NS) record for the zone.

The correct answer is A. Create an NS record named research in the adatum.com zone.

Explanation: Azure DNS is a hosting service that allows you to host your domain name system (DNS) domains in Azure. You can use Azure DNS to host your DNS domains and manage DNS records.

To delegate a subdomain named research.adatum.com to a different DNS server in Azure, you need to create an NS record named research in the adatum.com zone. An NS record (name server record) is a type of DNS record that specifies the name servers for a DNS zone. When you create an NS record for a subdomain, you're essentially delegating control of that subdomain to another DNS server.

To create an NS record in the Azure portal, follow these steps:

1. Go to the Azure portal and navigate to your DNS zone (adatum.com).
2. Click on the "Add record set" button.
3. In the "Name" field, enter "research".
4. In the "Type" dropdown list, select "NS".
5. In the "TTL" field, enter the time-to-live value for the record.
6. In the "NS record" field, enter the name of the DNS server that will be hosting the subdomain (e.g., ns1.research.adatum.com).

Once you've created the NS record, you'll need to configure the DNS server that will be hosting the subdomain (ns1.research.adatum.com in this case) to respond to DNS queries for the subdomain. This can typically be done using the DNS server's management console or command-line tools.

Option B (Create a PTR record named research in the adatum.com zone) is incorrect because a PTR record (pointer record) is used to map an IP address to a hostname, not a hostname to a DNS server.

Option C (Modify the SOA record of adatum.com) is incorrect because the SOA record (start of authority record) is used to identify the primary DNS server for a zone and contains information about the zone's configuration. Modifying the SOA record wouldn't delegate control of a subdomain to another DNS server.

Option D (Create an A record named *.research in the adatum.com zone) is incorrect because an A record (address record) is used to map a hostname to an IP address, not to delegate control of a subdomain to another DNS server.