Creating a Firewall opening using Powershell

Here is a quick solution to the challenge of creating a firewall opening on a Windows 7 or Windows 2008R2 server (should work on different version from Vista and above too ...).

Several settings are hardcoded, and others only support a limited number of settings (the function only supports TCP and UDP openings), but it can easily be extended if needed.

Function New-FirewallRule {

    Param(

        $name = "unnamed rule",

        $description = "made by PowerShell",

        $port = 666,

        $appName = $null,

        $serviceName = $null,

        [switch]$udp,

        [switch]$allprofiles

    )

    $firewallPolicy = New-Object -ComObject hnetcfg.fwpolicy2

    $firewallRule = New-Object -ComObject HNetCfg.FWRule

    if ($allprofiles) {

        $CurrentProfiles = 7 ## All profiles

    } else {

        $CurrentProfiles = $firewallPolicy.CurrentProfileTypes

    }

    if ($udp) {

        $protocol = 17 ## NET_FW_IP_PROTOCOL_UDP = 17

    } else {

        $protocol = 6 ## NET_FW_IP_PROTOCOL_TCP = 6

    }

    $firewallRule.name = $name

    $firewallRule.description = $description

    $firewallRule.protocol = $protocol

    $firewallRule.enabled = $true

    $firewallRule.localPorts = $port

    $firewallRule.action = 1  ## NET_FW_ACTION_ALLOW

    $firewallRule.grouping = "@firewallapi.dll,-23255"

    $firewallRule.profiles = $CurrentProfiles

    $firewallPolicy.Rules.Add($firewallRule)

}

To use the function to create a couple of SQL Server openings:

New-FirewallRule "SQL Server (1433/TCP)" "Made by Jakob" -Port 1433 -allprofiles

New-FirewallRule "SQL Server (1434/UDP)" "Made by Jakob" -Port 1434 -allprofiles -udp