15.2 Understanding DNS Settings in the DSfW Environment

15.2.1 General DNS Settings

The DSfW installation page requires details on the following objects:

  • Context of the DNS-DHCP Locator object

  • Context of the DNS-DHCP Group object

  • Context of the RootServerInfo object

DNS-DHCP Locator Object: The DNS-DHCP Locator object contains global defaults, DNS options, and a list of DNS servers and zones in the tree. The Java Management Console uses the Locator object to locate the object instead of searching the entire tree to display these objects.

DNSDHCP Group Object: The DNSDHCP-Group object is a standard eDirectory group object. The DNS servers gain access to the DNS data within the tree through the DNSDHCP-Group object.

RootServerInfo Object: The RootServInfo object is a container object that contains resource records for the DNS root servers. The resource record sets contain Name Server(NS)records and Address (A) records of name servers that provide pointers for DNS queries to the root servers. In addition to these objects, the following objects are required for DSfW:

  • DNS Server Object

  • DNS Zone Object

  • DNS Resource Record Set Object

  • DNS Resource Records

Only one copy of these objects exists in the DSfW tree. The DNS servers, DHCP servers, and the Microsoft Management Console must have access to these objects.

15.2.2 Configuring a Domain Controller as a Primary DNS Server

For a non-name-mapped setup, the contexts of the Locator object, RootServerInfo object, and the DNS-DHCP group object is automatically populated as the NCP server object location in the YaST page. By default, this context is ou=OESSystemObjects,<DomainDN>.

For a name-mapped setup, the fields are blank and the user can enter any context in the tree.For an additional domain controller configuration, the Locator and Group contexts are retrieved from the existing DNS server. This is also useful for administrators who might not want to configure many DNS services in a network.

The default refresh interval of the DNS server is 15 minutes. Any changes made to the DNS settings take effect in the subsequent refresh cycle. For the changes to be applied immediately, the DNS server (novell-named) must be restarted so that the DNS server reads the newer data from the server.A DNS administrator object must be created for DNS server configuration. Provide the name and the location of the DNS administrator object. This information is required only if you configure this server as a primary DNS server. For a forest root domain installation, the DNS is configured by default in first domain controller, so this information is required for DNS configuration.

While configuring first domain controller in any subsequent domain (except a forest root domain), the /etc/resolv.conf file must point to the existing DNS server. This is required to perform lookups during configuration. Later if you choose this server to be configured as a primary DNS server, the DNS configured on this server and the /etc/resolv.conf file gets automatically updated during provisioning and points to the local DNS server.

For information on installing and configuring OES DNS services, see Installing and Configuring DNS in the OES 2018 SP3: DNS/DHCP Services for Linux Administration Guide

15.2.3 Configuring a Domain Controller by Using an Existing DNS Server

When the first domain controller in a domain is using an existing DNS server, YaST provides an option to retrieve these values from the existing DNS server. During installation through YaST, you can retrieve these values by selecting Retrieve DNS entries, and then selecting Retrieve.

NOTE:If you are configuring an additional domain controller for a domain that is already configured to host a DNS server, make sure your first entry in the /etc/resolv.conf file is pointing to the DNS server that the first domain controller is using.