iperf3 命令

常用示例

说明

iperf3 is a network throughput testing tool that measures maximum TCP and UDP bandwidth performance. It creates data streams between a server and client to measure achievable network speed, useful for troubleshooting, benchmarking, and capacity planning. A typical test requires running iperf3 in server mode on one machine and client mode on another. The client initiates the test, and both sides report the measured throughput. By default, tests run for 10 seconds with TCP. TCP mode measures bulk transfer speed, limited by congestion control, RTT, and link capacity. UDP mode with -b sets a target send rate, useful for testing whether a network can sustain specific bandwidth without packet loss. Parallel streams (-P) can reveal aggregation limits and help saturate high-bandwidth links where a single stream can't achieve full capacity. The reverse mode (-R) tests upload by having the server send to the client. JSON output enables automated testing and integration with monitoring systems. Server can run as a daemon for ongoing availability.

参数

-s, --server

Run in server mode.

-c, --client _host_

Run as client, connect to server.

-p, --port _port_

Server port (default: 5201).

-t, --time _n_

Test duration in seconds (default: 10).

-P, --parallel _n_

Number of parallel streams.

-u, --udp

Use UDP instead of TCP.

-b, --bandwidth _nKMG_

Target bandwidth (UDP default: 1 Mbit/s).

-R, --reverse

Run in reverse mode (server sends, client receives).

--bidir

Bidirectional test simultaneously.

-i, --interval _n_

Seconds between periodic reports.

-n, --bytes _nKMG_

Number of bytes to transmit.

-J, --json

Output in JSON format.

-l, --length _nKMG_

Buffer/packet size.

-w, --window _nKMG_

Socket buffer size.

-B, --bind _addr_

Bind to specific address.

-4, -6

Use IPv4/IPv6 only.

-D, --daemon

Run server as daemon.

--logfile _file_

Write output to file.