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/