iperf3 is a network performance testing tool used to measure maximum bandwidth between TCP and UDP data streams. It can help you test the speed, latency, packet loss and other parameters of your network connection. Here are explanations of some commonly used options and parameters:
Common options:
-sOr--server: Run server mode.-cOr--client <host>: Run client mode and connect to the specified host.-pOr--port: Specify the server port to listen or connect.-fOr--format: Set the report format, such as Kbits, Mbits, KBytes, MBytes, etc.-iOr--interval: Set the number of seconds between periodic bandwidth reports.-dOr--debug: Output debugging information.
Server specific options:
-DOr--daemon: Run the server as a daemon.-IOr--pidfile file: write to PID file.-1Or--one-off: Exit after handling a client connection.
Client specific options:
-uOr--udp: use UDP instead of TCP.-bOr--bandwidth: Set the target bandwidth.-tOr--time: Set the transmission time (default is 10 seconds).-nOr--bytes: Set the number of bytes transferred.-lOr--len: Set the buffer length for reading or writing.-Por--parallel: Set the number of parallel client streams.-ROr--reverse: run in reverse mode (server sends, client receives).-wor--window: set window size/socket buffer size.-COr--congestion: Set TCP congestion control algorithm (Linux and FreeBSD only).-4Or--version4: use IPv4 only.-6Or--version6: use IPv6 only.
In addition, there are some other options to set the maximum segment size of TCP, SCTP, no delay, etc. as needed.
Overall, iperf3 is a powerful tool that can be used to comprehensively analyze and test network performance. By combining different parameters and options, you can perform detailed analysis and debugging for specific scenarios. When using, you must specify at least client mode ( -c) or server mode ( -s), otherwise the above parameter error message will appear.