One of the most handy tools for testing connectivity to remote hosts is the ping utility found in most operating systems. Named after sonar pinging, the tool sends Internet Control Message Protocol (ICMP) packets to a remote host and measures the time it takes to get there and back, helping you determine if a host is online and if there are problems reaching that host. The default packet size should be sufficient for most cases, but it's possible to change it to meet your specific testing needs.
Open a terminal window so you can work from the command line.
Type "ping -s
Stop the pings by pressing "ctrl+c" ("^c" in Mac OS X).