PowerShell New-NetFirewallRule

last modified February 15, 2025

This article covers the New-NetFirewallRule cmdlet in PowerShell. It creates inbound or outbound firewall rules in Windows. The cmdlet is part of the NetSecurity module. It provides granular control over Windows Firewall.

Firewall rule basics

A firewall rule defines how network traffic is filtered. Rules can allow or block traffic based on various criteria. Each rule has a name, direction, action, and protocol specification. Rules can apply to specific programs, ports, or IP addresses. Windows Firewall uses these rules to secure the system.

Create a basic allow rule

This example creates a simple inbound firewall rule. The rule allows traffic on TCP port 80. It applies to all profiles (Domain, Private, Public). The rule is enabled immediately after creation.

firewall1.ps1

New-NetFirewallRule -DisplayName “Allow HTTP” -Direction Inbound -Protocol TCP ` -LocalPort 80 -Action Allow -Enabled True

The rule allows incoming HTTP traffic on port 80. The -Direction parameter specifies inbound traffic. -Protocol defines the protocol type. -LocalPort sets the port number. -Action Allow permits the traffic.

Create a rule for a specific program

This example creates a rule for a specific executable file. The rule allows outbound traffic for the specified program. It applies only to the Private network profile. The rule has a custom description for documentation.

firewall2.ps1

New-NetFirewallRule -DisplayName “Allow MyApp” -Direction Outbound -Program "C:\Apps\MyApp.exe" -Action Allow -Profile Private -Description “Allows MyApp to communicate externally”

The -Program parameter specifies the application path. -Profile limits the rule to Private networks. -Description adds explanatory text. The rule only affects traffic from the specified executable.

Create a rule with IP restrictions

This example creates a rule with IP address restrictions. The rule allows inbound RDP traffic only from specific IPs. It uses the -RemoteAddress parameter to define allowed sources. The rule is disabled by default.

firewall3.ps1

New-NetFirewallRule -DisplayName “Restricted RDP” -Direction Inbound -Protocol TCP -LocalPort 3389 -Action Allow -RemoteAddress "192.168.1.100,192.168.1.101" -Enabled False

The rule would allow RDP access only from two IP addresses. -RemoteAddress accepts multiple comma-separated IPs. -Enabled False creates the rule in disabled state. The rule can be enabled later when needed.

Create a rule with service association

This example creates a rule associated with a Windows service. The rule allows inbound traffic for the DNS service. It uses the -Service parameter to link to the service. The rule applies to all network profiles.

firewall4.ps1

New-NetFirewallRule -DisplayName “Allow DNS Service” -Direction Inbound ` -Protocol UDP -LocalPort 53 -Action Allow -Service Dnscache

The rule allows DNS traffic on UDP port 53. -Service links to the Dnscache service. Traffic is only allowed when the service is running. This provides more precise control than port-based rules.

Create a rule with advanced security

This example creates a rule with advanced security settings. It configures authentication and encryption requirements. The rule uses IPSec for secure communication. Multiple security options are specified.

firewall5.ps1

New-NetFirewallRule -DisplayName “Secure File Share” -Direction Inbound -Protocol TCP -LocalPort 445 -Action Allow -Authentication Required -Encryption Dynamic -LocalUser Any -RemoteUser “DOMAIN\FileUsers”

The rule allows SMB traffic with security requirements. -Authentication enforces IPSec authentication. -Encryption enables dynamic encryption. -RemoteUser restricts access to specific domain users. This creates a secure file sharing rule.

Source

PowerShell documentation

In this article, we have covered the New-NetFirewallRule cmdlet in PowerShell.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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