Shulou(Shulou.com)06/01 Report--

Today, I will talk to you about how the Linux system counts the traffic in the high-speed network. Many people may not know much about it. In order to make you understand better, the editor has summarized the following contents for you. I hope you can get something according to this article.

Although there are many traffic monitoring tools in the Linux system, the system overhead of packet interception in the user space is so high that the traffic monitoring tools can not handle high-speed (above Gb) network interfaces.

Scripts are mainly based on the sysfs virtual file system, which is a mechanism used by the kernel to output device or driver-related information to user space. The relevant analysis data of the network interface will be output through "/ sys/class/net//statistics".

For example, eth0's network port analysis report is output to these files:

/ sys/class/net/eth0/statistics/rx_packets: received packet data

/ sys/class/net/eth0/statistics/tx_packets: number of packets transmitted

/ sys/class/net/eth0/statistics/rx_bytes: number of bytes received

/ sys/class/net/eth0/statistics/tx_bytes: number of bytes transferred

/ sys/class/net/eth0/statistics/rx_dropped: the amount of data that drops when a packet is received

/ sys/class/net/eth0/statistics/tx_dropped: the amount of data dropped by the transport packet

This data is automatically refreshed when the kernel data changes. Therefore, you can write a series of scripts to analyze and calculate traffic statistics. Here's the script (thanks to joemiller). The first script is to count the amount of data per second, including receiving (RX) or sending (TX). The latter is a description of the receive (RX) transmit (TX) bandwidth in network transmission. No tools are required for installation in these scripts.

Measure the packet per second of the network port:

#! / bin/bash

INTERVAL= "1" # update interval in seconds

If [- z "$1"]; then

Echo

Echo usage: $0 [network-interface]

Echo

Echo e.g. $0 eth0

Echo

Echo shows packets-per-second

Exit

Fi

IF=$1

While true

Do

R1=cat / sys/class/net/$1/statistics/rx_packets

T1=cat / sys/class/net/$1/statistics/tx_packets

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Sleep $INTERVAL

R2=cat / sys/class/net/$1/statistics/rx_packets

T2=cat / sys/class/net/$1/statistics/tx_packets

TXPPS=expr $T2-$T1

RXPPS=expr $R2-$R1

Echo "TX TXPPS pkts/s RX RXPPS pkts/s"

Done

Network bandwidth measurement

#! / bin/bash

INTERVAL= "1" # update interval in seconds

If [- z "$1"]; then

Echo

Echo usage: $0 [network-interface]

Echo

Echo e.g. $0 eth0

Echo

Exit

Fi

IF=$1

While true

Do

R1=cat / sys/class/net/$1/statistics/rx_bytes

T1=cat / sys/class/net/$1/statistics/tx_bytes

Sleep $INTERVAL

R2=cat / sys/class/net/$1/statistics/rx_bytes

T2=cat / sys/class/net/$1/statistics/tx_bytes

TBPS=expr $T2-$T1

RBPS=expr $R2-$R1

TKBPS=expr $TBPS / 1024

RKBPS=expr $RBPS / 1024

Echo "TX TKBPS kb/s RX RKBPS kb/s"

Done

The screenshot below shows the output of the two scripts above.

What is Linux system Linux is a free-to-use and free-spread UNIX-like operating system, is a POSIX-based multi-user, multi-task, multi-threaded and multi-CPU operating system, using Linux can run major Unix tools, applications and network protocols.

After reading the above, do you have any further understanding of how the Linux system counts the traffic in high-speed networks? If you want to know more knowledge or related content, please follow the industry information channel, thank you for your support.

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