iPerf Usage

Side A (Host 10.20.20.100 doing the connection to 172.16.20.100 )

iperf -c 172.16.20.100 -w 4mb

Side B (Host 172.16.20.100 listening for the connection)

iperf -s

Result:

iperf -c 172.16.20.100 -w 4mb
------------------------------------------------------------
Client connecting to 172.16.20.100, TCP port 5001
TCP window size: 3.81 MByte
------------------------------------------------------------
[128] local 10.20.20.100 port 3460 connected with 172.16.20.100 port 5001
[ ID] Interval       Transfer     Bandwidth
[128]  0.0-12.2 sec  21.0 MBytes  14.5 Mbits/sec

Command Reference:

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 <filename> output the report or error message to this specified 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 <host> bind to <host>, 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 <host> run in client mode, connecting to <host>
-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 <name> 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)

Miscellaneous:
-h, –help print this message and quit
-v, –version print version information and quit

[KM] Indicates options that support a K or M suffix for kilo- or mega-

The TCP window size option can be set by the environment variable TCP_WINDOW_SIZE. Most other options can be set by an environment variable IPERF_<long option name>, such as IPERF_BANDWIDTH.