1.Ping Ping is a important tool used very commonly to check, the host is online or not means, its is connected to network or not. It also mean, the host we are trying to ping is accessible from your computer or not. I am showing you the example in the picture shown below-
2.Tracert Tracert is a command tool used to trace the route from your computer to Host computer . It uses ICMP (internet control messaging protocol) to trace the route. It just lists the hops or routers comes in between while reaching the host computer from your own computer.
3.Nslookup Nslookup is a command line tool which acts like a reverse-dns of any Ip address. This resolves the Ip address to Domain name.Just see below to know more
4.Netstat Netstat is a tool to list the connections to foreign addresses with their port numbers . This is very useful tool. It lists all the TCP and UDP connections . Command is “netstat -an”