netsh.md

To block:

netsh advfirewall set allprofiles firewallpolicy blockinbound,blockoutbound

To allow:

netsh advfirewall set allprofiles firewallpolicy allowinbound,allowoutbound

To reset:

netsh advfirewall reset

To show the current settings:

netsh advfirewall show allprofiles

To show the current settings in a more readable format:

netsh advfirewall show allprofiles | findstr "State"

IP lookup from DNS:

$ips = (Resolve-DnsName codeforces.com -ErrorAction Stop | Where-Object { $_.IPAddress -match '^\d+.\d+.\d+.\d+$' } | Select-Object -ExpandProperty IPAddress) -join ','

Allow only a specific IP address:

netsh advfirewall firewall add rule name="Allow Codeforces" dir=out action=allow protocol=any remoteip=$ips

To see our rules:

netsh advfirewall firewall show rule name="Allow Codeforces"

Get-NetFirewallRule -PolicyStore PersistentStore | Where-Object { $_.Enabled -eq $true } | Format-Table -AutoSize