Usage: iperf [-s|-c host] [options] iperf [-h|--help] [-v|--version] Client/Server: -f, --format [kmKM] format to report: Kbits, Mbits, KBytes, MBytes -i, --interval # seconds between periodic bandwidth reports -l, --len #[KM] length of buffer to read or write (default 8 KB) -m, --print_mss print TCP maximum segment size (MTU - TCP/IP header) -o, --output output the report or error message to this specifie d file -p, --port # server port to listen on/connect to -u, --udp use UDP rather than TCP -w, --window #[KM] TCP window size (socket buffer size) -B, --bind bind to , an interface or multicast address -C, --compatibility for use with older versions does not sent extra msgs -M, --mss # set TCP maximum segment size (MTU - 40 bytes) -N, --nodelay set TCP no delay, disabling Nagle's Algorithm -V, --IPv6Version Set the domain to IPv6 Server specific: -s, --server run in server mode -D, --daemon run the server as a daemon -R, --remove remove service in win32 Client specific: -b, --bandwidth #[KM] for UDP, bandwidth to send at in bits/sec (default 1 Mbit/sec, implies -u) -c, --client run in client mode, connecting to -d, --dualtest Do a bidirectional test simultaneously -n, --num #[KM] number of bytes to transmit (instead of -t) -r, --tradeoff Do a bidirectional test individually -t, --time # time in seconds to transmit for (default 10 secs) -F, --fileinput input the data to be transmitted from a file -I, --stdin input the data to be transmitted from stdin -L, --listenport # port to recieve bidirectional tests back on -P, --parallel # number of parallel client threads to run -T, --ttl # time-to-live, for multicast (default 1)