The Add-DnsClientNrptRule cmdlet in PowerShell is a powerful tool for configuring DNS resolution rules on Windows operating systems. These rules are part of the Name Resolution Policy Table (NRPT), which allows you to define specific DNS settings for different namespaces. This can be particularly useful in environments where you need to direct DNS queries for certain domains to specific DNS servers, such as in split-brain DNS configurations or when implementing DirectAccess.

Examples:

Example 1: Basic DNS Rule Configuration

To create a simple DNS resolution rule that directs queries for a specific domain to a designated DNS server, you can use the following PowerShell command:

Add-DnsClientNrptRule -Namespace ".example.com" -NameServers "192.168.1.1"

In this example, any DNS queries for domains ending in .example.com will be sent to the DNS server at 192.168.1.1.

Example 2: Configuring a Rule with Additional Options

You can also configure more complex rules with additional options. For instance, you might want to use a specific DNS server only when connected to a particular network interface:

Add-DnsClientNrptRule -Namespace ".example.com" -NameServers "192.168.1.1" -InterfaceAlias "Ethernet"

This command specifies that the DNS rule should only apply when the system is connected via the network interface named "Ethernet".

Example 3: Using the NRPT Rule for DNS Suffix

If you want to apply a DNS rule based on a DNS suffix, you can do so with the following command:

Add-DnsClientNrptRule -Namespace ".example.com" -DnsSuffix "corp.example.com" -NameServers "192.168.1.2"

This command routes DNS queries for the corp.example.com suffix through the DNS server 192.168.1.2.

Example 4: Removing a DNS Client NRPT Rule

If you need to remove an NRPT rule, you can use the Remove-DnsClientNrptRule cmdlet. Here’s an example:

Remove-DnsClientNrptRule -Namespace ".example.com"

This command removes any NRPT rules associated with the .example.com namespace.

Important Considerations

• Ensure that you have administrative privileges when executing these commands, as modifying DNS settings requires elevated permissions.
• Be cautious when configuring DNS rules, as incorrect settings can lead to resolution issues or unintended network behavior.