INetFwPolicy2

INetFwPolicy2 is a COM interface that provides programmatic access to the Windows Firewall with Advanced Security policy. It exposes the firewall's configuration and policy state to software, enabling queries and changes to how the firewall handles network traffic.

The interface is exposed by the Windows Firewall service and is available on Windows Vista and later. It supports per-profile configuration across the Domain, Private, and Public network profiles and can report which profiles are currently active. Through INetFwPolicy2, applications can enable or disable the firewall, set default inbound and outbound actions, and enumerate or modify firewall rules and rule groups.

Developers typically access INetFwPolicy2 via COM bindings described in the NetFwTypeLib type library or through the ProgID HNetCfg.FwPolicy2 (for example, by creating a COM object in PowerShell with New-Object -ComObject HNetCfg.FwPolicy2).

Use of the interface is common in enterprise administration and security software to automate policy deployment, auditing, and rule management. Operations that modify policy generally require elevated privileges and may trigger user prompts depending on system settings. INetFwPolicy2 is considered the successor to the older INetFwPolicy interface used in earlier firewall APIs.