Windows 7 / Networking

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Creating resource records

When you run your own DNS server, you create a resource record for each host name that you want to be accessible by the rest of the network.

There are several different types of resource records used by DNS servers, the most important of which are as follows:

• SOA (Start of Authority): Indicates that the server is the best authoritative source for data concerning the zone. Each zone must have an SOA record, and only one SOA record can be in a zone.
• NS (Name Server): Identifies a DNS server functioning as an authority for the zone. Each DNS server in the zone (whether primary master or secondary) must be represented by an NS record.
• A (Address): Provides a name-to-address mapping that supplies an IPv4 address for a specific DNS name. This record type performs the primary function of the DNS, converting names to addresses.
• AAAA (Address): Provides a name-to-address mapping that supplies an IPv6 address for a specific DNS name. This record type performs the primary function of the DNS, converting names to addresses.
• PTR (Pointer): Provides an address-to-name mapping that supplies a DNS name for a specific address in the in-addr.arpa domain. This is the functional opposite of an A record, used for reverse lookups only.
• CNAME (Canonical Name): Creates an alias that points to the canonical name (that is, the "real" name) of a host identified by an A record. Administrators use CNAME records to provide alternative names by which systems can be identified.
• MX (Mail Exchanger): Identifies a system that will direct e-mail traffic sent to an address in the domain to the individual recipient, a mail gateway, or another mail server.

To create a new Address resource record, use the following procedure.

1. Log on to Windows Server 2012 using an account with Administrative privileges. The Server Manager window opens.
2. Click Tools > DNS to open the DNS Manager console.
3. Expand the server node and select the Forward Lookup Zones folder.
4. Right-click the zone in which you want to create the record and, from the shortcut menu, select New Host (A or AAAA). The New Host dialog box appears.
5. In the Name text box, type the host name for the new record. The FQDN for the record appears.
6. In the IP Address text box, type the IPv4 or IPv6 address associated with the host name.
7. Select the following check boxes, if necessary:
   • Create Associated Pointer (PTR) Record: Creates a reverse name lookup record for the host in the in-addr.arpa domain
   • Allow Any Authenticated User To Update DNS Records With The Same Owner Name: Enables users to modify their own resource records
8. Click Add Host. The new resource record is created in the zone you selected.
9. Close the DNS Manager console.

To create a PTR record for a new host, you can select the Create Associated Pointer (PTR) Record check box in the New Host dialog box, but that will only be effective if a reverse lookup zone already exists on the server. To create the zone, you follow the same procedure described earlier, this time selecting the Reverse Lookup Zones folder.

When you elect to create an IPv4 reverse lookup zone, a Reverse Lookup Zone Name page appears, in which you supply the Network ID that the wizard will use to create the zone.

Once the zone is created, you can either create PTR records along with A or AAAA records, or you create a new PTR record, using the New Resource Record dialog box.

Configuring DNS server settings

Once you have installed a DNS server and created zones and resource records on it, there are many settings you can alter to modify its behavior. The following sections describe some of these settings.

CONFIGURING ACTIVE DIRECTORY DNS REPLICATION

To modify the replication scope for an Active Directory-integrated zone, open the zone's Properties sheet in the DNS Manager console, and on the General tab, click Change for Replication: All DNS Servers In The Active Directory Domain to display the Change Zone Replication Scope dialog box. The options are the same as those in the New Zone Wizard.

Every DNS server must be able to contact the root name servers to initiate name resolution processes. Most server implementations, including Microsoft DNS Server, are preconfigured with the names and addresses of multiple root name servers. These are called root hints.

The 13 root name server names are located in a domain called root-servers.net, and are named using letters of the alphabet. The servers are scattered around the world on different subnets to provide fault tolerance.

To modify the root hints on a Windows Server 2012 DNS server, right-click the server node, open the Properties sheet, and click the Root Hints tab. On this tab, you can add, edit, or remove root hints from the list provided.