我试图在我的两台机器之间进行测试，输出如下：
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.100.113, port 41749
[ 5] local 192.168.100.114 port 5201 connected to 192.168.100.113 port 41750
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-1.00 sec 479 MBytes 4.02 Gbits/sec
[ 5] 1.00-2.00 sec 611 MBytes 5.13 Gbits/sec
[ 5] 2.00-3.00 sec 615 MBytes 5.16 Gbits/sec
[ 5] 3.00-4.00 sec 614 MBytes 5.15 Gbits/sec
[ 5] 4.00-5.00 sec 616 MBytes 5.17 Gbits/sec
[ 5] 5.00-6.00 sec 597 MBytes 5.01 Gbits/sec
[ 5] 6.00-7.00 sec 519 MBytes 4.35 Gbits/sec
[ 5] 7.00-8.00 sec 561 MBytes 4.70 Gbits/sec
[ 5] 8.00-9.00 sec 590 MBytes 4.95 Gbits/sec
[ 5] 9.00-10.00 sec 600 MBytes 5.03 Gbits/sec
[ 5] 10.00-10.05 sec 27.5 MBytes 4.47 Gbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-10.05 sec 0.00 Bytes 0.00 bits/sec sender
[ 5] 0.00-10.05 sec 5.69 GBytes 4.87 Gbits/sec receiver
$ iperf3 -c 192.168.100.114 -w 300k
Connecting to host 192.168.100.114, port 5201
[ 4] local 192.168.100.113 port 41750 connected to 192.168.100.114 port 5201
[ ID] Interval Transfer Bandwidth Retr Cwnd
[ 4] 0.00-1.00 sec 506 MBytes 4.24 Gbits/sec 0 216 KBytes
[ 4] 1.00-2.00 sec 613 MBytes 5.14 Gbits/sec 0 216 KBytes
[ 4] 2.00-3.00 sec 613 MBytes 5.14 Gbits/sec 0 216 KBytes
[ 4] 3.00-4.00 sec 615 MBytes 5.16 Gbits/sec 0 216 KBytes
[ 4] 4.00-5.00 sec 617 MBytes 5.18 Gbits/sec 0 216 KBytes
[ 4] 5.00-6.00 sec 595 MBytes 4.99 Gbits/sec 0 216 KBytes
[ 4] 6.00-7.00 sec 515 MBytes 4.32 Gbits/sec 0 216 KBytes
[ 4] 7.00-8.00 sec 565 MBytes 4.74 Gbits/sec 0 216 KBytes
[ 4] 8.00-9.00 sec 590 MBytes 4.95 Gbits/sec 0 216 KBytes
[ 4] 9.00-10.00 sec 601 MBytes 5.05 Gbits/sec 0 216 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 5.69 GBytes 4.89 Gbits/sec 0 sender
[ 4] 0.00-10.00 sec 5.69 GBytes 4.89 Gbits/sec receiver
从客户端站点的输出，我们可以看到有发送方和接收方流量记录，但从服务器站点，只有接收方流量。
与我以反向模式运行相比，服务器站点没有接收器流量。
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.100.113, port 41755
[ 5] local 192.168.100.114 port 5201 connected to 192.168.100.113 port 41756
[ ID] Interval Transfer Bandwidth Retr Cwnd
[ 5] 0.00-1.00 sec 611 MBytes 5.13 Gbits/sec 0 212 KBytes
[ 5] 1.00-2.00 sec 629 MBytes 5.28 Gbits/sec 0 212 KBytes
[ 5] 2.00-3.00 sec 637 MBytes 5.35 Gbits/sec 0 212 KBytes
[ 5] 3.00-4.00 sec 642 MBytes 5.39 Gbits/sec 0 212 KBytes
[ 5] 4.00-5.00 sec 641 MBytes 5.38 Gbits/sec 0 212 KBytes
[ 5] 5.00-6.00 sec 643 MBytes 5.39 Gbits/sec 0 212 KBytes
[ 5] 6.00-7.00 sec 638 MBytes 5.35 Gbits/sec 0 212 KBytes
[ 5] 7.00-8.00 sec 641 MBytes 5.38 Gbits/sec 0 212 KBytes
[ 5] 8.00-9.00 sec 630 MBytes 5.29 Gbits/sec 0 212 KBytes
[ 5] 9.00-10.00 sec 637 MBytes 5.35 Gbits/sec 0 212 KBytes
[ 5] 10.00-10.04 sec 19.9 MBytes 4.15 Gbits/sec 0 212 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth Retr
[ 5] 0.00-10.04 sec 6.22 GBytes 5.32 Gbits/sec 0 sender
[ 5] 0.00-10.04 sec 0.00 Bytes 0.00 bits/sec receiver
$ iperf3 -c 192.168.100.114 -w 300k -R
Connecting to host 192.168.100.114, port 5201
Reverse mode, remote host 192.168.100.114 is sending
[ 4] local 192.168.100.113 port 41756 connected to 192.168.100.114 port 5201
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-1.00 sec 631 MBytes 5.29 Gbits/sec
[ 4] 1.00-2.00 sec 630 MBytes 5.29 Gbits/sec
[ 4] 2.00-3.00 sec 638 MBytes 5.35 Gbits/sec
[ 4] 3.00-4.00 sec 641 MBytes 5.38 Gbits/sec
[ 4] 4.00-5.00 sec 640 MBytes 5.37 Gbits/sec
[ 4] 5.00-6.00 sec 643 MBytes 5.39 Gbits/sec
[ 4] 6.00-7.00 sec 641 MBytes 5.38 Gbits/sec
[ 4] 7.00-8.00 sec 639 MBytes 5.36 Gbits/sec
[ 4] 8.00-9.00 sec 631 MBytes 5.29 Gbits/sec
[ 4] 9.00-10.00 sec 636 MBytes 5.34 Gbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 6.22 GBytes 5.34 Gbits/sec 0 sender
[ 4] 0.00-10.00 sec 6.22 GBytes 5.34 Gbits/sec receiver
有人可以帮忙解释为什么吗？非常感谢。