Linux带宽测试
iperf是linux下一款非常实用的测带宽工具，是C/S模型的，支持使用TCP和UDP测试，可以测试带宽，丢包（丢包指的是UDP的丢包，TCP丢包会重传）等信息。若想使用此工具必须服务端必须是公网可访问的机器。
iperf原理
服务端监听监听在某个端口，客户端对该端口发送流量，由此可以测的客户端带宽的相关信息。（由于一般都是测试服务器的带宽，因此测试的时候需要有两台拥有公网地址的机器）。
带宽换算
通信公司说的带宽一般为Gb/s 、Mb/s；而我们使用的带宽实际说的是GB/s、MB/s;所以通信公司所给的带宽需要除以8进行换算。
以下分别用两台带宽分别为5Mb与100Mb的的主机互相进行测试
ct5 代表带宽为5Mb的主机
ct100 代表带宽为100Mb的主机
一、安装
以Centos8为例
[root@01-0001 yum.repos.d]# wget https://download-ib01.fedoraproject.org/pub/epel/8/Everything/aarch64/Packages/e/epel-release-8-16.el8.noarch.rpm
[root@01-0001 yum.repos.d]# rpm -ivh epel-release-8-16.el8.noarch.rpm
[root@01-0001 yum.repos.d]# yum install iperf
二、测试
测试5M带宽的主机，带宽是否为能达到5M
1.tcp方式
服务器端
[root@ecs-29d1 ~]# iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[ 4] local 192.168.1.77 port 5001 connected with 36.112.130.213 port 57730 (peer 2.1.6)
[ ID] Interval Transfer Bandwidth
[ 4] 0.0-10.4 sec 6.13 MBytes 4.95 Mbits/sec
[ 4] local 192.168.1.77 port 5001 connected with 36.112.130.213 port 57732 (peer 2.1.6)
[ 4] 0.0-10.3 sec 6.00 MBytes 4.88 Mbits/sec
客户端：
[root@01-0001 ~]# iperf -c ct100 -t 10 -i 1
------------------------------------------------------------
Client connecting to ct100, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.0.215 port 57732 connected with 36.112.136.105 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-1.00 sec 768 KBytes 6.29 Mbits/sec
[ 1] 1.00-2.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 2.00-3.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 3.00-4.00 sec 512 KBytes 4.19 Mbits/sec
[ 1] 4.00-5.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 5.00-6.00 sec 384 KBytes 3.15 Mbits/sec
[ 1] 6.00-7.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 7.00-8.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 8.00-9.00 sec 512 KBytes 4.19 Mbits/sec
[ 1] 9.00-10.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 10.00-10.33 sec 128 KBytes 3.21 Mbits/sec
[ 1] 0.00-10.33 sec 6.00 MBytes 4.87 Mbits/sec
2.udp方式
服务器端：
[root@ecs-29d1 ~]# iperf -s -u
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 byte datagrams
UDP buffer size: 208 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.1.77 port 5001 connected with 36.112.130.213 port 44211 (peer 2.1.6)
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[ 3] 0.0-10.0 sec 1.25 MBytes 1.05 Mbits/sec 0.017 ms 1/ 895 (0.11%)
[ 4] local 192.168.1.77 port 5001 connected with 36.112.130.213 port 55893 (peer 2.1.6)
[ 4] 0.0-10.0 sec 6.04 MBytes 5.07 Mbits/sec 0.018 ms 4612/ 8920 (52%)
[ 3] local 192.168.1.77 port 5001 connected with 36.112.130.213 port 47713 (peer 2.1.6)
[ 4] local 192.168.1.77 port 5001 connected with 36.112.130.213 port 45984 (peer 2.1.6)
[ 4] 0.0-30.1 sec 5.53 MBytes 1.54 Mbits/sec 0.030 ms 4973/ 8920 (56%)
[ 5] local 192.168.1.77 port 5001 connected with 36.112.130.213 port 44776 (peer 2.1.6)
[ 5] 0.0-46.1 sec 5.75 MBytes 1.05 Mbits/sec 0.021 ms 360/ 4462 (8.1%)
[ 4] local 192.168.1.77 port 5001 connected with 36.112.130.213 port 52849 (peer 2.1.6)
[ 4] 0.0-59.5 sec 5.37 MBytes 757 Kbits/sec 0.050 ms 632/ 4462 (14%)
客户端：
//设置为10M带宽进行测试
[root@01-0001 ~]# iperf -c ct100 -t 10 -i 1 -u -b 10M
------------------------------------------------------------
Client connecting to ct100, UDP port 5001
Sending 1470 byte datagrams, IPG target: 1121.52 us (kalman adjust)
UDP buffer size: 208 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.0.215 port 45984 connected with 36.112.136.105 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-1.00 sec 1.25 MBytes 10.5 Mbits/sec
[ 1] 1.00-2.00 sec 1.25 MBytes 10.5 Mbits/sec
[ 1] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec
[ 1] 3.00-4.00 sec 1.25 MBytes 10.5 Mbits/sec
[ 1] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec
[ 1] 5.00-6.00 sec 1.25 MBytes 10.5 Mbits/sec
[ 1] 6.00-7.00 sec 1.25 MBytes 10.5 Mbits/sec
[ 1] 7.00-8.00 sec 1.25 MBytes 10.5 Mbits/sec
[ 1] 8.00-9.00 sec 1.25 MBytes 10.5 Mbits/sec
[ 1] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec
[ 1] 0.00-10.00 sec 12.5 MBytes 10.5 Mbits/sec
[ 1] Sent 8921 datagrams
[ 1] Server Report:
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[ 1] 0.00-0.00 sec 0.000 Bytes -nan bits/sec 131.073 ms 4294966296/0 (inf%)
//设置为5M带宽进行测试
[root@01-0001 ~]# iperf -c ct100 -t 10 -i 1 -u -b 5M
------------------------------------------------------------
Client connecting to ct100, UDP port 5001
Sending 1470 byte datagrams, IPG target: 2243.04 us (kalman adjust)
UDP buffer size: 208 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.0.215 port 44776 connected with 36.112.136.105 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-1.00 sec 642 KBytes 5.26 Mbits/sec
[ 1] 1.00-2.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 2.00-3.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 3.00-4.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 4.00-5.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 5.00-6.00 sec 639 KBytes 5.23 Mbits/sec
[ 1] 6.00-7.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 7.00-8.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 8.00-9.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 9.00-10.00 sec 640 KBytes 5.24 Mbits/sec
[ 1] 0.00-10.00 sec 6.26 MBytes 5.25 Mbits/sec
[ 1] Sent 4463 datagrams
[ 1] Server Report:
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[ 1] 0.00-0.00 sec 0.000 Bytes -nan bits/sec 131.073 ms 4294966296/0 (inf%)
用UDP测试时注意查看服务端的丢包情况，可以发现当设置带宽为10M，会有接近50%的丢包，而当带宽设置为5M，丢包显著下降只有10%左右，而带宽设置为1M的时候，丢包为0.11%，说明了客户端带宽为5M左右，同时也说明UDP本身传输就不可靠，即使带宽设置的很低也存在丢包。
同理测试100M主机的带宽
//服务端
[root@01-0001 ~]# iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.0.215 port 5001 connected with 36.112.136.105 port 52722
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-10.04 sec 104 MBytes 87.3 Mbits/sec
[ 2] local 192.168.0.215 port 5001 connected with 36.112.136.105 port 52724
[ ID] Interval Transfer Bandwidth
[ 2] 0.00-10.08 sec 109 MBytes 90.4 Mbits/sec
//客户端
[root@ecs-29d1 ~]# iperf -c ct5 -t 10 -i 1
------------------------------------------------------------
Client connecting to ct5, TCP port 5001
TCP window size: 374 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.1.77 port 52724 connected with 36.112.130.213 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 1.0 sec 5.62 MBytes 47.2 Mbits/sec
[ 3] 1.0- 2.0 sec 12.4 MBytes 104 Mbits/sec
[ 3] 2.0- 3.0 sec 12.0 MBytes 101 Mbits/sec
[ 3] 3.0- 4.0 sec 11.2 MBytes 94.4 Mbits/sec
[ 3] 4.0- 5.0 sec 10.5 MBytes 88.1 Mbits/sec
[ 3] 5.0- 6.0 sec 11.5 MBytes 96.5 Mbits/sec
[ 3] 6.0- 7.0 sec 12.2 MBytes 103 Mbits/sec
[ 3] 7.0- 8.0 sec 11.8 MBytes 98.6 Mbits/sec
[ 3] 8.0- 9.0 sec 9.62 MBytes 80.7 Mbits/sec
[ 3] 9.0-10.0 sec 11.8 MBytes 98.6 Mbits/sec
[ 3] 0.0-10.1 sec 109 MBytes 90.6 Mbits/sec
iperf常用参数说明：
适用客户端/服务器：
-f --格式[k|m|K|M] 分别表示以Kbits、Mbits、KBytes、MBytes显示报告，默认是Mbits
-i 以秒为单位统计带宽值
-l 读写缓冲区大小，默认是8KB
-m 显示最大的TCP数据段大小 (MTU - TCP/IP header)
-o 将报告和错误信息输出到文件
-p 指定服务器和客户端连接的端口
-u 使用udp协议
-w 指定TCP窗口大小，默认是8KB
-B 绑定一个主机地址或接口（当主机有多个地址或接口时使用该参数）
-C 兼容旧版本（当server端和client端版本不一样时使用）
-M 设定TCP数据包的最大mtu值
-N 设定TCP不延时
-V 传输ipv6数据包适用服务器端：
-s 以服务器模式启动
-U 单线程UDP模式下运行
-D 以守护进程模式运行适用客户端：
-b 指定客户端通过UDP协议发送信息的带宽，默认值为1Mbit/s
-c 指定服务器地址
-d 同时进行双向传输测试
-n 指定传输的字节数
-r 单独进行双向传输测试
-t 指定Iperf测试时间，默认10秒
-F 指定需要传输的文件
-I 从标准输入（stdin）中读取要传输的数据
-L 指定一个端口，服务器将利用这个端口与客户机连接
-P 客户端到服务器的连接数，默认值为1
-T 指定ttl值带宽也可以配合scp进行快速测试，只需一个公网地址，节省资源
ct100为带宽100Mb/s的主机
[root@zyq tmp]# scp -P 5499 ct100:/boot/initramfs-0-rescue-6748d698cc244bdebd23ef4793c8dd1d.img /tmp/
initramfs-0-rescue-6748d698cc244bdebd23ef4793c8dd1d.img 100% 56MB 8.5MB/s 00:06
ct5为带宽5Mb/s的主机
[root@zyq tmp]# scp ct5:/boot/initramfs-4.18.0-240.el8.x86_64.img /tmp/
initramfs-4.18.0-240.el8.x86_64.img 100% 28MB 576.2KB/s 00:49