Specifications

Default is 5001, the same as ttcp.
-u, --udp $IPERF_UDP
Use UDP rather than TCP. See also the -b option.
-w, --window
#[KM]
$TCP_WINDOW_SIZE
Sets the socket buffer sizes to the specified value. For TCP, this
sets the TCP window size. For UDP it is just the buffer which
datagrams are received in, and so limits the largest receivable
datagram size.
-B, --bind
host
$IPERF_BIND
Bind to host, one of this machine's addresses. For the client this
sets the outbound interface. For a server this sets the incoming
interface. This is only useful on multihomed hosts, which have
multiple network interfaces.
For Iperf in UDP server mode, this is also used to
bind and join to a multicast group. Use addresses in
the range 224.0.0.0 to 239.255.255.255 for multicast.
See also the
-T option.
-C, --
compatibility
$IPERF_COMPAT
Compatibility mode allows for use with older version of iperf.
This mode is not required for interoperability but it is highly
recommended. In some cases when using representative
streaming you could cause a 1.7 server to crash or cause
undesired connection attempts.
-M, --mss
#[KM}
$IPERF_MSS
Attempt to set the TCP maximum segment size (MSS) via the
TCP_MAXSEG option. The MSS is usually the MTU - 40 bytes
for the TCP/IP header. For ethernet, the MSS is 1460 bytes
(1500 byte MTU). This option is not implemented on many
OSes.
-N, --nodelay $IPERF_NODELAY
Set the TCP no delay option, disabling Nagle's algorithm.
Normally this is only disabled for interactive applications like
telnet.
-V (from v1.6 or
higher)
.
Bind to an IPv6 address
Server side:
$ iperf -s -V
Client side:
$ iperf -c <Server IPv6 Address> -V
Note: On version 1.6.3 and later a specific IPv6 Address does
not need to be bound with the
-B option, previous 1.6 versions
do. Also on most OSes using this option will also respond to
IPv4 clients using IPv4 mapped addresses.
Server specific options
-s, --server $IPERF_SERVER
Run Iperf in server mode.
-D (from v1.2 or
higher)
.
Run the server as a daemon (Unix platforms)
On Win32 platforms where services are available, Iperf will start
running as a service.
-R (only for
Windows, from v1.2
or higher)
. Remove the Iperf service (if it's running).
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