To do this, open Spotlight by clicking the magnifying glass at the top-right corner of the screen, type terminal, and then click Terminal in the search results. Use this method to see if a port is open on your local router or access point. The router's IP address appears next to "default" at the top of the results. For example, if you wanted to see if port 25 is open on your router, and your router's IP address is 10.0.0.1, you would type nc -vz 10.0.0.1 25. Here's how to interpret the results:  If the port is open, you'll see a message that says the connection succeeded. If the port is closed, you'll see a message that says the connection was refused or timed out.

How would you rephrase that briefly using Vietnamese?
Mở cửa sổ Terminal. Nhập netstat –nr | grep default vào dấu nhắc lệnh rồi nhấn ⏎ Return. Nhập nc –vz (địa chỉ IP bộ định tuyến) (cổng). Nhấn ⏎ Return.