Testing the bandwidth of gigabit NICs in CentOS

Iperf is a pure bandwidth test software based on the C/S model. It can test the network card throughput.

The advantage of iperf is to simply send and receive packets, to prevent hard disks from dragging down and affecting the test results.

This document uses a gigabit Nic Bcom 5720 as a test environment CentOS 6.4x64

Install iperf on both machines

Yuminstalliperf -- enablerepo = epel

Start one of them as a server and open the firewall port 5001.

Iperf-s-I 1-w 448 k

The startup result is as follows:

Server listening on TCP port 5001TCP window size: 448 KByte

Connect to the server as a client on the other server for 10 minutes

Iperf-c 10.10.10.22-I 1-w 448 k-t 600

The server displays the following information:

[4] local10.10.22 port 5001 connected with 10.10.11 port 56251 [ID] Interval Transfer Bandwidth [4] 0.0-1.0 sec 112 MBytes 941 Mbits/sec [4] 1.0-2.0 sec 112 MBytes 941 mbits/sec [4] 2.0-3.0 sec 112 MBytes 941 Mbits/sec [4] 3.0-4.0 sec 112 MBytes 941 Mbits/sec [4] 4.0-5.0 sec 112 MBytes 941 Mbits /sec [4] 5.0-6.0 sec 112 MBytes 941 Mbits/sec [4] 6.0-7.0 sec 112 MBytes 941 Mbits/sec [4] 7.0-8.0 sec 112 MBytes 941 Mbits/ sec

The client information is

3] 46.0-47.0 sec 112 MBytes 942 Mbits/sec [ID] Interval Transfer Bandwidth [3] 47.0-48.0 sec 112 MBytes 941 Mbits/sec [ID] Interval Transfer Bandwidth [3] 48.0-49.0 sec 112 MBytes 942 Mbits/sec [ID] Interval Transfer Bandwidth [3] 49.0-50.0 sec 112 MBytes 941 Mbits/sec [ID] Interval Transfer Bandwidth [3] 50.0- 51.0 sec 112 MBytes 942 Mbits/sec [ID] Interval Transfer Bandwidth [3] 51.0-52.0 sec 112 MBytes 941 Mbits/sec [ID] Interval Transfer Bandwidth [3] 52.0-53.0 sec 112 MBytes 941 Mbits/sec [ID] Interval Transfer Bandwidth [3] 53.0-54.0 sec 112 MBytes 942 Mbits/sec [ID] Interval Transfer Bandwidth [3] 54.0-55.0 sec 112 MBytes 941 Mbits/sec

The above information shows that the current network adapter transmission speed is about 940 Mbit/s, close to the theoretical speed of 1 G/s, download speed of 112 M/s, close to the theoretical speed of 125 M/s, through cacti bandwidth monitoring, the preceding statistics are also displayed.

At this point, the Gigabit Nic has been verified.

Note that there are many possible reasons for the impact on bandwidth:

1. The vswitch is a 10-Gigabit communication hub

2. The gigabit Nic works in the 10-Gigabit mode, and none of the machines involved in the test work in the 10-Gigabit Nic mode.

3. Use real hard disk files to test the disk speed.