Server or Client: -p, --port # server port to listen on/connect to -f, --format format to report: Kbits, Mbits, Gbits, Tbits -i, --interval # seconds between periodic throughput reports -F, --file name xmit/recv the specified file -A, --affinity n/n,m set CPU affinity -B, --bind <host> bind to the interface associated with the address <host> -V, --verbose more detailed output -J, --json output in JSON format --logfile f send output to a log file --forceflush force flushing output at every interval -d, --debug emit debugging output -v, --version show version information and quit -h, --help show this message and quitServer specific: -s, --server run in server mode -D, --daemon run the server as a daemon -I, --pidfile file write PID file -1, --one-off handle one client connection then exit --rsa-private-key-path path to the RSA private key used to decrypt authentication credentials --authorized-users-path path to the configuration file containing user credentialsClient specific: -c, --client <host> run in client mode, connecting to <host> --sctp use SCTP rather than TCP -X, --xbind <name> bind SCTP association to links --nstreams # number of SCTP streams -u, --udp use UDP rather than TCP --connect-timeout # timeout for control connection setup (ms) -b, --bitrate # target bitrate in bits/sec (0 for unlimited) (default 1 Mbit/sec for UDP, unlimited for TCP) (optional slash and packet count for burst mode) --pacing-timer # set the timing for pacing, in microseconds (default 1000) --fq-rate # enable fair-queuing based socket pacing in bits/sec (Linux only) -t, --time # time in seconds to transmit for (default 10 secs) -n, --bytes # number of bytes to transmit (instead of -t) -k, --blockcount # number of blocks (packets) to transmit (instead of -t or -n) -l, --length # length of buffer to read or write (default 128 KB for TCP, dynamic or 1460 for UDP) --cport <port> bind to a specific client port (TCP and UDP, default: ephemeral port) -P, --parallel # number of parallel client streams to run -R, --reverse run in reverse mode (server sends, client receives) --bidir run in bidirectional mode. Client and server send and receive data. -w, --window # set window size / socket buffer size -C, --congestion <algo> set TCP congestion control algorithm (Linux and FreeBSD only) -M, --set-mss # set TCP/SCTP maximum segment size (MTU - 40 bytes) -N, --no-delay set TCP/SCTP no delay, disabling Nagle's Algorithm -4, --version4 only use IPv4 -6, --version6 only use IPv6 -S, --tos N set the IP type of service, 0-255. The usual prefixes for octal and hex can be used, i.e. 52, 064 and 0x34 all specify the same value. --dscp N or --dscp val set the IP dscp value, either 0-63 or symbolic. Numeric values can be specified in decimal, octal and hex (see --tos above). -L, --flowlabel N set the IPv6 flow label (only supported on Linux) -Z, --zerocopy use a 'zero copy' method of sending data -O, --omit N omit the first n seconds -T, --title str prefix every output line with this string --extra-data str data string to include in client and server JSON --get-server-output get results from server --udp-counters-64bit use 64-bit counters in UDP test packets --repeating-payload use repeating pattern in payload, instead of randomized payload (like in iperf2) --username username for authentication --rsa-public-key-path path to the RSA public key used to encrypt authentication credentials indicates options that support a K/M/G suffix for kilo-, mega-, or giga- iperf3 homepage at: https://software.es.net/iperf/Report bugs to: https://github.com/esnet/iperf