NAME

       tcpspray - TCP/IP bandwidth measurement tool (Discard and Echo client)

SYNOPSIS

       tcpspray [-46ev] [-b block_size] [-d wait_µs] [ -f filename] [-n count] <hostname> [port]

DESCRIPTON

       tcpspray uses the Discard resp. Echo protocol (RFC 863 resp. RFC 862) to perform bandwidth
       measurements of TCP sessions between the local system, and a Discard resp. Echo server.

       Unix-based hosts can provide a Discard and/or Echo servers with the Internet  super-server
       inetd. On Windows NT, the simple network protocols optional component will do the same.

       The  name or address of the server node must be specified. tcpspray will automatically try
       to use IPv6 when available. If not, or if it fails, it will  fallback  to  IPv4.  However,
       tcpspray4 resp. tcpspray6 only try to use IPv4 resp. IPv6.

OPTIONS

       -4 or --ipv4
              Force usage of TCP over IPv4.

       -6 or --ipv6
              Force usage of TCP over IPv6.

       -b block_size or --bsize block_size
              Send block of the specified byte size (default: 1024).

       -d wait_µs or --delay wait_µs
              Waits  for  the  given  amount  of  microseconds  after  any  given was sent before
              attempting to send the next one. There is no delay by default.

       -e or --echo
              Use the Echo protocol instead of Discard. tcpspray will measure the  time  required
              to send data and receive it back, instead of simply sending it.

       -f filename or --fill filename
              Read  data from the specified file to fill sent blocks with. If the file is smaller
              than the size of blocks, or if no file were specified, the remaining trailing bytes
              are all set to zero.

       -h or --help
              Display some help and exit.

       -n block_count or --count block_count
              Send the specified amount of data blocks for the measurements (default: 100).

       -V or --version
              Display program version and license and exit.

       -v or --verbose
              Display  more  verbose  informations. In particular, tcpspray will print a dot each
              time a block is sent. If the Echo protocol is used (option -e), dots will be erased
              as data is received back.

DIAGNOSTICS

       If you get no response while you know the remote host is up, it is most likely that it has
       no Discard/Echo service running, or that these services are blocked by a firewall. Running
       tcptraceroute6(8)  resp.   tcptraceroute(8)  toward  the IPv6 resp. IPv4 remote host might
       help detecting such a situation.

SECURITY

       tcpspray does not require any privilege to run.

SEE ALSO

       tcp(7), inetd(8), tcptraceroute6(8), tcptraceroute(8)

AUTHOR

       Rémi Denis-Courmont <remi at remlab dot net>

       http://www.remlab.net/ndisc6/