Usage: iperf [-s|-c host] [options]
iperf [-h|–help] [-v|–version]
Server or Client:
-p, –port # server port to listen on/connect to
-f, –format [kmgKMG] format to report: Kbits, Mbits, KBytes, MBytes
-i, –interval # seconds between periodic bandwidth reports
-F, –file name xmit/recv the specified file
-B, –bind <host> bind to a specific interface
-V, –verbose more detailed output
-J, –json output in JSON format
–logfile f send output to a log file
-d, –debug emit debugging output
-v, –version show version information and quit
-h, –help show this message and quit
Server 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
Client specific:
-c, –client <host> run in client mode, connecting to <host>
-u, –udp use UDP rather than TCP
-b, –bandwidth #[KMG][/#] target bandwidth in bits/sec (0 for unlimited)
(default 1 Mbit/sec for UDP, unlimited for TCP)
(optional slash and packet count for burst mode)
-t, –time # time in seconds to transmit for (default 10 secs)
-n, –bytes #[KMG] number of bytes to transmit (instead of -t)
-k, –blockcount #[KMG] number of blocks (packets) to transmit (instead of -t or -n)
-l, –len #[KMG] length of buffer to read or write
(default 128 KB for TCP, 8 KB 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)
-w, –window #[KMG] set window size / socket buffer size
-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’
-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
–get-server-output get results from server
–udp-counters-64bit use 64-bit counters in UDP test packets