Ping – this is a utility to test network connectivity. The way it works is, in general terms, sending host echo request and waiting for the echo reply from him. Each node must be able to accept Internet echo requests and echo answers back, of course, if it is connected to the network and working.

No echo reply from the server indicates whether the server "hanging" or there is permanent damage to the network on the client server, get around to "bypass", which is impossible.

This property makes a convenient tool health check ping node and link integrity. However, a negative result of the ping does not always indicate the existence of any problem