Simple Network Performance Test

To do a simple and quick network performance test the ftp command can be used.
FTP on Linux and other Unix systems allows you to pass shell commands to the ftp client by using the pipe symbol ‘|’ as the first character of the file name. With this feature you can send a very large file to a remote host using /dev/zero as input and /dev/null as output.
Example:

ftp> put "|dd if=/dev/zero bs=1M count=100" /dev/null

This command transfers a large file without involving the disk and without having to cache the file in memory. If you use a large file on a disk it might become a bottleneck. In this example, "|dd if=/dev/zero bs=1M count=100″ becomes the input file. Since a dd command without the "of=" paramater prints the content of the file to standard output (stdout), the ftp client can read the output and pass it on to the remote file which is /dev/null on the remote host.