How to Configure Windows Firewall: Rules, Ports, and Blocking Apps

Windows Firewall blocks unauthorized network traffic by default. Most users never touch it — but when you need to open a port, block an app, or troubleshoot a connection issue, knowing how it works saves time.

Check Firewall Status

Get-NetFirewallProfile | Select-Object Name, Enabled

All three profiles (Domain, Private, Public) should show Enabled: True. If any is disabled:

Set-NetFirewallProfile -All -Enabled True

Allow an App Through Firewall

GUI: Win + R → firewall.cpl → Allow an app or feature through Windows Defender Firewall → Change settings → Allow another app → Browse to the executable.

PowerShell:

New-NetFirewallRule -DisplayName "My App" `
  -Direction Inbound `
  -Program "C:\Program Files\MyApp\myapp.exe" `
  -Action Allow `
  -Profile Private,Public

Open a Specific Port

Common need: game servers, web servers, remote tools.

# Open TCP port 8080 inbound
New-NetFirewallRule -DisplayName "HTTP 8080" `
  -Direction Inbound `
  -Protocol TCP `
  -LocalPort 8080 `
  -Action Allow

# Open UDP port 27015 (game server example)
New-NetFirewallRule -DisplayName "Game Server UDP" `
  -Direction Inbound `
  -Protocol UDP `
  -LocalPort 27015 `
  -Action Allow

Block an App from Accessing the Internet

Useful for blocking telemetry, preventing a program from phoning home, or restricting a specific app.

# Block outbound for a specific executable
New-NetFirewallRule -DisplayName "Block MyApp Outbound" `
  -Direction Outbound `
  -Program "C:\Program Files\MyApp\myapp.exe" `
  -Action Block

Block a Specific IP Address

# Block inbound from specific IP
New-NetFirewallRule -DisplayName "Block IP" `
  -Direction Inbound `
  -RemoteAddress "192.168.1.100" `
  -Action Block

# Block a range
New-NetFirewallRule -DisplayName "Block IP Range" `
  -Direction Inbound `
  -RemoteAddress "10.0.0.0/8" `
  -Action Block

List and Manage Existing Rules

# List all enabled inbound rules
Get-NetFirewallRule -Direction Inbound -Enabled True | Select-Object DisplayName, Action, Profile

# Find rule by name
Get-NetFirewallRule -DisplayName "*Remote Desktop*"

# Disable a rule without deleting
Disable-NetFirewallRule -DisplayName "My App"

# Delete a rule
Remove-NetFirewallRule -DisplayName "My App"

Advanced Firewall (wf.msc)

For more control: Win + R → wf.msc

This opens Windows Defender Firewall with Advanced Security — shows all rules, allows filtering by profile, protocol, port, and program simultaneously. Useful for diagnosing why something is blocked.

Right-click Inbound Rules → New Rule for a wizard that covers all scenarios.

Reset to Defaults

If firewall rules become a mess:

netsh advfirewall reset

This removes all custom rules and restores factory defaults. All custom Allow/Block rules will be deleted.

Common Scenarios

Need	Direction	What to specify
Run a local web server	Inbound	TCP port 80/443
Allow RDP	Inbound	TCP port 3389
Block app from internet	Outbound	Program path
Block a suspicious IP	Inbound	Remote IP address
Allow VPN traffic	Inbound/Outbound	Protocol + port

Summary

For most cases: use New-NetFirewallRule in PowerShell — faster than the GUI. For complex rules combining program + port + IP, use wf.msc. Always specify the correct direction — inbound for connections coming in, outbound for connections going out.