Command Line utilities to check TCP/IP configurations
Every Command Line includes network tools and these help check your adapter configuration, DHCP information, active connections, and more.
The most basic one is ipconfig (ifconfig in linux and mac). This let's you see all connected network adapters and corresponding IP, gateway, subnet mask, mac address and other details. Windows users can just type ipconfig in Command Prompt or Powershell. Linux and Mac users can type ifconfig in terminal.
The next one is netstat and it is same for all Operating Systems. Netstat gives information like active connections, protocol details, routing table and other TCP details. Type netstat -h to check all options available.