作用：基于TCP或UDP，对网络带宽吞吐量进行测试
安装：yum install iperf3 -y
服务端参数：
-s：表示启动服务端
-i：表示打印报告的时间间隔
-p：指定监听端口，默认为5201
-D：以后台方式运行（默认是前台运行，将测试结果打印在屏幕）
用法示例：iperf3 -s -i 1 -p 10000
客户端参数：
-c：表示启动客户端，后边跟上服务端IP
-b：指定目标的最大带宽（用ethtool 网卡名字可以查看）
-t：指定测试时间
-P：指定并发数
-p：指明服务端启动的端口
-R：逆向测试
-d：双向测试
用法示例：iperf3 -c 192.168.0.30 -b 1G -t 5 -P 2 -p 10000
举例说明：
#启动服务端
[root@test02 ~]# iperf3 -s -i 1 -p 10000
-----------------------------------------------------------
Server listening on 10000
-----------------------------------------------------------
Accepted connection from 192.168.10.121, port 40322
[ 5] local 192.168.10.122 port 10000 connected to 192.168.10.121 port 40324
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-1.00 sec 110 MBytes 926 Mbits/sec
[ 5] 1.00-2.00 sec 121 MBytes 1.02 Gbits/sec
[ 5] 2.00-3.00 sec 117 MBytes 980 Mbits/sec
[ 5] 3.00-4.00 sec 119 MBytes 997 Mbits/sec
[ 5] 4.00-5.00 sec 120 MBytes 1.01 Gbits/sec
[ 5] 5.00-5.00 sec 0.00 Bytes 0.00 bits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-5.00 sec 0.00 Bytes 0.00 bits/sec sender
[ 5] 0.00-5.00 sec 587 MBytes 984 Mbits/sec receiver#启动客户端
[root@test01 ~]# iperf3 -c 192.168.10.122 -t 5 -b 1G -P 1 -p 10000 -R
Connecting to host 192.168.10.122, port 10000
Reverse mode, remote host 192.168.10.122 is sending
[ 4] local 192.168.10.121 port 40328 connected to 192.168.10.122 port 10000
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-1.00 sec 108 MBytes 909 Mbits/sec
[ 4] 1.00-2.00 sec 122 MBytes 1.02 Gbits/sec
[ 4] 2.00-3.00 sec 118 MBytes 992 Mbits/sec
[ 4] 3.00-4.00 sec 119 MBytes 999 Mbits/sec
[ 4] 4.00-5.00 sec 120 MBytes 1.00 Gbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-5.00 sec 587 MBytes 985 Mbits/sec 0 sender
[ 4] 0.00-5.00 sec 587 MBytes 985 Mbits/sec receiver可以看到发送方和接收方的Bandwidth（带宽）大概都是985M/s，很接近网卡的1000M/s；
来源：oschina
链接：https://my.oschina.net/u/4264209/blog/3220569