Iperf v3.0.11

Tags： iperf 性能测试 网络工具

Iperf is a bandwidth testing tool that can help users identify issues within their internet connection. If you suspect that your internet is not performing as smoothly as it should, you can run this software on each computer at the end of the data connection to perform a quick test. Iperf does not require installation and can test both TCP and UDP, assessing network jitter and potential issues. You can download the official Iperf software for free from the Multisoft website.

Software Features:

Accurately measures internet bandwidth.

Reports MSS/MTU values and observations.

Supports TCP window scaling.

Utilizes thread synchronization when P processes or Win32 threads are available.

Supports multiple simultaneous connections between the client and server.

Note: Some company security settings may classify this tool as hacking software. If security personnel have any doubts, it is advisable for network administrators to check with them before downloading or using the software.

How to Use Iperf:

Windows Installation: Simply copy the downloaded iperf.exe and cygwin1.dll files to the %systemroot% directory.

Linux Installation: Use the following command to install:

gunzip -c iperf-.tar.gz | tar -xvf -cd iperf-./configuremakemake install

Using Iperf (Windows Example): To run Iperf, enter the iperf command in the cmd. Use iperf –help to view the help documentation for Iperf commands.

Testing Single-Core TCP:

Server: Run Iperf and enter the command iperf –s –p 12345 –i 1 –M to start Iperf on port 12345.

Client: Run Iperf and enter the command iperf –c server-ip –p server-port –i 1 –t 10 –w 20K. Parameters:

-c: Client mode, followed by the server IP.

-p: Followed by the server's listening port.

-i: Sets the interval for bandwidth reports, in seconds.

-t: Sets the duration of the test, in seconds.

-w: Sets the TCP window size, generally not needed as the default is usually sufficient.

Testing Single-Core UDP (Default Bandwidth):

Server: Run Iperf and enter the command iperf –s -u –p 12345 –i 1 to start Iperf on port 12345 in UDP mode.

Client: Run Iperf and enter the command iperf -c server-ip -p server-port -i 1 -t 10 -b. Parameters:

-c: Client mode, followed by the server IP.

-p: Followed by the server's listening port.

-i: Sets the interval for bandwidth reports, in seconds.

-t: Sets the duration of the test, in seconds.

-b: Sets the UDP bandwidth, in bits per second.

Iperf Commands:

-f, --format [bkmaBKMA]: Resets bandwidth output to factory settings. Supported formats include: 'b' = bits/sec, 'B' = Bytes/sec, 'k' = Kbits/sec, 'K' = KBytes/sec, 'm' = Mbits/sec, 'M' = MBytes/sec, 'g' = Gbits/sec, 'G' = GBytes/sec, 'a' = adaptive bits/sec, 'A' = adaptive Bytes/sec. The responsive format is either kilo- or mega-. All fields except bandwidth are output in bytes unless specified, with the default parameter being 'a'.

Note: When estimating byte count, Kilo = 1024, Mega = 1024^2, Giga = 1024^3. Typically, in networking, Kilo = 1000, Mega = 1000^2, and Giga = 1000^3. Therefore, Iperf calculates bits accordingly. If this confuses you, use the -f b parameter and calculate manually.

-i, --interval #: Sets the interval between each report, in seconds. If set to a non-zero value, reports will be output at this interval. The default is zero.

-l, --len #[KM]: Sets the length of the read/write buffer. The default for TCP is 8KB, and for UDP, it is 1470 bytes.

-m, --print_mss: Outputs the TCP MSS value (based on TCP_MAXSEG). The MSS value is generally 40 bytes less than the MTU value.

Server-Specific Options:

-s, --server perf: Server mode.

-D (v1.2 or later versions): Runs Iperf as a background xinetd service on Unix platforms. On Win32 platforms, Iperf runs as a service.

-R (v1.2 or later versions, for Windows only): Uninstalls the Iperf service if it is running.

-o (v1.2 or later versions, for Windows only): Redirects output to a specified file.

-c, --client host: If Iperf is running in server mode and a server is specified with the -c parameter, Iperf will only accept connections from the specified server. This parameter does not work in UDP mode.

Client-Specific Options:

-b, --bandwidth #[KM]: Bandwidth to use for UDP mode, in bits per second. This option is related to -u. The default is 1 Mbit/sec.

-c, --client host: Runs Iperf in client mode, connecting to the specified Iperf server.

-r, --tradeoff: Round-trip test mode. When the client-to-server test is complete, the server will connect back to the client on the port specified by -L (or the default port used by the client to connect to the server). The reverse connection will start when the client connection stops. If you need to perform a dual test simultaneously, try the -d parameter.

-t, --time #: Sets the total time for the transfer. Iperf will repeatedly send data of a specified length within the specified time. The default is approximately 10 seconds. Refer to -l and -n options.

-L, --listenport: Specifies the port for the server to connect back to the client. The default uses the port the client connects to the server.

-P, --parallel: Number of connections. Specifies the number of connections to be used between the client and server. The default is 1 process. This parameter must be used simultaneously by both the client and server.

Changelog:

Added features.

Fixed bugs.

We heartily recommend Iperf as a powerful network performance testing tool. Iperf can help users test the quality of TCP and UDP bandwidth. If you suspect that your internet is not running smoothly, you can run this software on each computer at the end of the data connection to perform a quick test. Why not try other software such as {recommendWords} and see if you like it!