Managing dynamic domains in Microsoft Windows infrastructure

Dynamic DNS (DDNS) is a method that allows the automatic updating of a domain name system (DNS) in real-time, with the active DNS configuration of its configured hostnames, addresses, or other information. Microsoft DNS supports DDNS, which is particularly useful in environments where devices frequently change their IP addresses, such as those using DHCP.

Integration with DHCP

• Automatic Updates: When a DHCP server assigns a new IP address to a device, it can automatically update the DNS server with the new address. This integration ensures that the DNS records always reflect the current IP addresses of network devices.
• Renewal:Lease> As DHCP leases are renewed, the DNS records are updated accordingly. If a device's IP address changes, the DNS server is informed immediately.

Enable DDNS (Dynamic DNS ) for the domain you create or a current domain already defined in your Microsoft DNS server by enabling the DDNS option. Once DDNS is enabled for an IPv4 domain the following options are automatically enabled for the domain.

These options include : DNS Domain Name (Option id: 15) and Domain Name Server(Option id: 6)

Note: Enabling DDNS for a IPv6 domain does not enable the relevant DHCPv6 options for the relevant domain or the DNS server. You'll have to enable them manually at the Global level or the scope level

Scope, Policy or cluster-specific configuration: Option 6 and 15 can be configured at the cluster or global level, scope level, or policy level, providing flexibility to assign different domain names to different clients matching specific criteria.

DDNS configurations can be fine-tuned to have granular control over the choice of domain names for the clients drawing leases from a particular subnet or scope, global (cluster) level , or policy level. For this,

• Get into the DHCP module.
• Navigate to the required section:

  Scope level: Navigate to DHCP-> Network->Subnet. Open the subnet of your choice in the Edit mode or create one. Find the Options tab at the extreme bottom and select the Vendor class as DHCP Standard Options.

  Policy level: Navigate to DHCP-> Network->Policy. Open the Policy of your choice in the Edit mode or create one. Find the Options tab at the extreme bottom and select the Vendor class as DHCP Standard Options.

  Global(cluster) level: Navigate to DHCP-> Network->Config within the DHCP module to program the DHCP server level configurations. Navigate to the Options tab and select the Vendor class as DHCP Standard Options.

• Once the Vendor Class is chosen, the Options drop-down list box displays the list of already defined options under DHCP Standard Options. From the tray of DHCP standard options that drops down select the below options and enter the relevant values respectively.
• DNS Domain Name (Option id: 15)- This option specifies the IP addresses of the DNS servers that client computers should use for DNS resolution.
• Domain Name Server(Option id: 6)- This option specifies the DNS domain name that client computers should use for DNS resolution, which is essential for ensuring proper network communication and resource access within a domain.
• Enter the value(s) for the options' parameter(s).
• Click the Add button after each entry.
• If you are within the Scope level or Policy level, when you are done with the selection, click Save to finalize the configurations.

Advanced DNS settings for dynamic uptates to domains

DDI Central offers certain advanced DNS settings for fine-tuning control over dynamic updates delivered by the DHCP server to the DDNS clients. These settings can be configured at the Global (Cluster) level, subnet(scope) or the policy level.

Navigate to the required section:

Scope level: Navigate to DHCP-> Network->Subnet. Open the subnet of your choice in the Edit mode or create one. Find the DNS Settings tab at the extreme bottom.

>Policy level: Navigate to DHCP-> Network->Policy. Open the Policy of your choice in the Edit mode or create one. Find the DNS Settings tab at the extreme bottom

Global (cluster) level: Navigate to DHCP-> Network->Config within the DHCP module to program the DHCP server to manage standalone dynamic DNS settings. Navigate to the DNS Settings tab.

DNS Settings

These attributes ensure more efficient and accurate management of both DHCP and DNS services within the network.

Dynamic updates enables the DHCP server to automatically update DNS records when a DHCP lease is issued, renewed, or released.

Update older clients ensures that even legacy devices or older clients that do not support dynamic DNS can still have their DNS records updated by the DHCP server.

Disabling PTR updates prevents the DHCP server from creating or updating reverse lookup records.In a network where reverse DNS lookups are not required or for security reasons, an administrator might disable PTR updates to reduce DNS record management overhead.

Note: Options, Custom options and DNS settings can be defined at the global level (Top level or cluster level) standalone, subnet level and also coupled with the conditions defined under the named DHCP policies.