We can use one of the networking commands in Unix. It is called ping. With ping command we can ping a remote host.
Ping utility sends packets in an IP network with ICMP protocol. Once the packet goes from source to destination and comes back it records the time.
We can even specify the number of packets we want to send so that we collect more statistics to confirm the result.
% ping www.google.com
Another option is to use telnet to remote host to check its status.Read the full book at www.amazon.com