On Windows systems, netstat.exe is a useful utility to check for open ports and listeners. However, the tool returns text only, has cryptic arguments, and isn’t available cross-platform.
On Windows systems, you can use a new PowerShell cmdlet named Get-NetTCPConnection which mimics much of the functionality found in netstat.exe. For example, you can list all HTTPS connections (port 443) currently open by any of your software (browsers):
PS> Get-NetTCPConnection -RemotePort 443 -State Established LocalAddress LocalPort RemoteAddress RemotePort State AppliedSetting OwningProcess ------------ --------- ------------- ---------- ----- -------------- ------------- 192.168.2.105 58640 52.114.74.221 443 Established Internet 14204 192.168.2.105 56201 52.114.75.149 443 Established Internet 9432 192.168.2.105 56200 52.114.142.145 443 Established Internet 13736 192.168.2.105 56199 13.107.42.12 443 Established Internet 12752 192.168.2.105 56198 13.107.42.12 443 Established Internet 9432 192.168.2.105 56192 40.101.81.162 443 Established Internet 9432 192.168.2.105 56188 168.62.58.130 443 Established Internet 10276 192.168.2.105 56181 168.62.58.130 443 Established Internet 10276 192.168.2.105 56103 13.107.6.171 443 Established Internet 9432 192.168.2.105 56095 13.107.42.12 443 Established Internet 9432 192.168.2.105 56094 13.107.43.12 443 Established Internet 9432 192.168.2.105 55959 140.82.112.26 443 Established Internet 21588 192.168.2.105 55568 52.113.206.137 443 Established Internet 13736 192.168.2.105 55555 51.103.5.186 443 Established Internet 12752 192.168.2.105 49638 51.103.5.186 443 Established Internet 5464
Unfortunately, Get-NetTCPConnection has severe limitations. For example, it does not resolve IP addresses or process IDs, so you can’t easily discover the server names you are connected to, and the programs maintaining the connections. And it is available on Windows systems only.
Let’s lift these limitations one by one in the next parts.
