How to Check Network Connection by use of Commands in linux

You need to use any one of the following tool or command under Linux to check network connections including their state, source/destination, and addresses and bandwidth usage etc:

1. ss command: It dump socket (network connection) statistics such as all TCP / UDP connections, established connection per protocol (e.g., display all established ssh connections), display all the tcp sockets in various state such as ESTABLISHED or FIN-WAIT-1 and so on.
2. netstat command: It can display network connections, routing tables, interfaces and much more.
3. tcptrack and iftop commands: Displays information about TCP connections it sees on a network interface and display bandwidth usage on an interface by host respectively.