Although ping does not completely isolate problems, you can use it to help identify where a problem lies. When troubleshooting with ping, take the following steps:
ping the IP address of your local loopback, using the command ping 127.0.0.1. If this command is successful, you know that the TCP/IP protocol suite is installed correctly on your system and functioning. If you are unable to ping the local loopback adapter, TCP/IP might need to be reloaded or reconfigured on the machine you are using.
The Loopback Address
The loopback is a special function within the protocol stack that is supplied for troubleshooting purposes. The Class A IP address 127.X.X.X is reserved for the loopback; although convention dictates that you use 127.0.0.1, you can use any address in the 127.X.X.X range, except for the network number itself (127.0.0.0) and the broadcast address (127.255.255.255). You can also ping by using the default hostname for the local system, which is called localhost (for example, ping localhost).
ping the assigned IP address of your local network interface card (NIC). If the ping is successful, you know that your NIC is functioning on the network and has TCP/IP correctly installed. If you are unable to ping the local NIC, TCP/IP might not be bound correctly to the NIC or the NIC drivers might be improperly installed.
ping the IP address of another known good system on your local network. By doing so, you can determine whether the computer you are using can see other computers on the network. If you can ping other devices on your local network, you have network connectivity.
If you cannot ping other devices on your local network and you were able to ping the IP address of your system, you might not be connected to the network correctly.
After you've confirmed that you have network connectivity for the local network, you can verify connectivity to a remote network by sending a ping to the IP address of the default gateway.
If you are able to ping the default gateway, you can verify remote connectivity by sending a ping to the IP address of a system on a remote network.
Using just the ping command in these steps, you can confirm network connectivity on not only the local network, but also on a remote network. The whole process requires as much time as it takes to type in the command, and you can do it all from a single location.
If you are an optimistic person, you can perform step 5 first. If that works, all the other steps will also work, saving you the need to test them. If your step 5 trial fails, you can go back to step 1 and start the troubleshooting process from the beginning.