Port 135 is the RPC Endpoint Mapper. It acts as a directory service for DCOM (Distributed Component Object Model) applications. When a client wants to communicate with a remote Windows service (like the Registry or Service Control Manager), they first query port 135 to find the dynamic port assigned to that service.

Before opening a new port, it’s helpful to see what is already active. You can do this quickly using the Command Prompt , and press Enter. Type the following command and hit Enter: netstat -ano

Each open port reduces your attack surface. Key risks include:

Further reading:

To open port 8080 via PowerShell (Admin):

The netstat command is the classic "old school" method that remains highly effective for a quick audit. : netstat -ano | findstr LISTENING What the flags mean : -a : Displays all connections and listening ports. -n : Displays addresses and port numbers in numerical form.

: In the left pane, click Inbound Rules , then select New Rule... in the right-hand "Actions" pane . Rule Type : Select Port and click Next . Protocol & Port :

OK OK OK OK OK OK OK