netem commands

First, Netem and TC:Netem is a network emulation function module provided by Linux 2.6 and above kernel versions. The function module can be used to simulate complex Internet transmission performance in a well-performing LAN, such as low bandwidth, transmission delay, packet loss and so on. Many distributions of Linux with Linux 2.6 (or more) versions of the kernel feature the kernel, such as Fedora, Ubuntu, Redhat, OpenSuse, CentOS, Debian, and more.

the first token bucketMTU is the size of the second token bucketBurst>mtuIf the token in the token bucket is not enough, the packet will have to wait for a certain time, the time is controlled by the latency parameter, if the wait time exceeds latency, then the packet will be discardedThe limit parameter is a setting that allows the maximum number of data to wait in the queueLatency=max ((Limit-burst)/rate, (LIMIT-MTU)/peakrate);Burst should be greater than MTU and rateOverhead represents the e

Linux network traffic control tool-Netem Article 1: ConceptsNetem is a network simulation function module provided by Linux 2.6 and later kernel versions. This function module can be used to simulate complex Internet transmission performance in a LAN with good performance, such as low bandwidth, transmission latency, and packet loss. Many released Linux versions that use the Linux 2.6 (or later) kernel have enabled this kernel function, such as Fedora

Why do I use Netem to do a flow controlBut when sending, feel really send the data when still did not reach every packet is a 1s delay ah, here the 1s delay is what mean ah?The delay here is not to say that each packet is delay 5s, but that after delay5s, all of a sudden sent out?sudo tc qdisc add dev eth0 root netem delay 100sAll eth0 packets have to be delayed by 100s, starting with the queue, and we star

% indicates the Ting Time Range is 100 ms ± 10 ms * 25% Port packet loss command: # tc qdisc change dev eth0 root netem loss 0.1% packet loss rate is 0. 1% # tc qdisc change dev eth0 root netem loss 0.3% 25% packet loss rate range: 0. 3% 25%) [edit] [ed data packet Copy command # tc qdisc change dev eth0 root netem duplicate 1% Packet copy rate 1% [edit] [edi pac

Summary of delay commands for simulating packet loss in centosSummary of delay commands for simulating packet loss in linux:First, run the ifconfig command.1. Set latencyLatency: sudo tc qdisc add dev eth0 root netem delay 30 msLatency in the range (10-50 ms): sudo tc qdisc add dev eth0 root netem delay 30 ms 20 msSet

A repeated instruction is a set of instructions for operating the data buffer. The data buffer is usually a byte array, which can be a single word or double word. (Intel 'calls these commands string commands) The most common data buffer operation commands are movsx, CMPs, stosx, and scasx. X can be B or W, and D represents byte, word, and dual-word, respectively

1. Getting Help information: ManMan ls: Get help with ls commandMan services: View the Help information for profile services, directly add the file name, no absolute path requiredHelp: 1 indicates help for the command, 5 indicates help for the configuration fileMans 1 passwd2. View the command description: Whatis3. Production See profile information: Apropos profile Name3. Get help with Shell built-in commands:Help umask: View the umask command's helpful information4. Options for viewing

administrator-M: Specifies that the group member and-a use almost-R: Remove password-r: Restrict user login group, only members in group can join the group with NEWGRPGpasswdgroupname : If the system has a Peter account, the account itself is not a member of the GroupName group, use NEWGRP need to enter a passwordLet the user temporarily join the group, and then the file group created by Peter will be groupname. So this way you can temporarily let Peter build the textUse other groups instead of

Tags: CPU BSP picture com inux font exit ptime UIOne, use W to view the system loadW, uptime View system load, 0.00 means 1 minutes load 0Cat/proc/cpuinfo View CPU CoresSecond, Vmstat command, view process, CPU, memory, swap, IO, systemR, SWPD, Si, so, Bi, bo, US, WADynamic display 5 times per secondRun, block process waits, swap partition memory is not enough to put,Si/so how many kilobytes of data from swap into/out memory, Bi/bo read/write memory from disk, US user consumes CPU percentage, do

Statements in assembly language programs can be composed of commands, pseudo commands, and macro commands. Command: Each Command corresponds to a CPU operation. A pseudo-command is also called a pseudo-operation. It is an operation processed by the assembler during the compilation of the source program, they can complete functions such as processor selection, def

Linux commands-ls commands and linux commands ls Today, we will introduce common commands in Linux. First, we will introduce the most frequently used commands in Linux-the ls command.For more information about Linux commands, see

Ten commands required for Linux commands and ten commands for linux Linux has now become the most popular Operating System in the software industry. Mastering Linux has become a required professional skill for every developer.In order to help you learn, I hope you can master the ten commands that you must master when

Explanation of transclude options and ng-transclude commands in angular. js commands, and angularjsng commands Preface Before starting this article, we must first describe that the angular version we use is 1.5.0, because different versions have different performance results. First, we should understand that one option in the angular command is transclude, which

Common Linux commands-permission management commands-Other permission management commands, and common command permission management Command name: chownEnglish: change file ownership Command path:/bin/chown Syntax: chown [user] [file or directory] Function Description: Change the owner of a file or directory. Example: chown shenchao fengjieChange the owner o

Help commands for common linux commands and common linux commands 1.TypeThe difference between built-in and external commands 2.BashEnter bash to use help in bash. 3.Help lsLs is an external command, help can only view the built-in command methods, cd is a built-in command Ls -- helpAvailable 4.Man lsMan does not

Add user Two-step walk: 1.useradd username 2.passwd PSRights Management CommandsCommand name:chmod->>change The permissions mode of a fileCommand path:/bin/chmodExecute Permissions: All UsersSyntax: chmod [{u g o} {+-=}{rwx}][file or directory][mode = 421] [File or directory]+: Increase Permissions-: Reduce permissions=: Give permission directlythe focus of mastery is to use the digital way of authority control, r=4 w=2 x=1.rwxr-xr--= 754Rw-r-x--x = 651Example: chmod g+w filechmod 777 FileRWX Pe

I. Shell special symbol, Cut command* Any character[Email protected] ~]# Ls/tmp/*.txt/tmp/1.txt/tmp/2.txt/tmp/q.txt[Email protected] ~]#？ Any one character[Email protected] ~]# Mkdir/tmp/test1[Email protected] ~]# Touch/tmp/test1[Email protected] ~]# ls-d/tmp/test?/tmp/test1[Email protected] ~]##注释字符[Email protected] ~]# sdx=233 #assa[Email protected] ~]# echo $SDX233[Email protected] ~]#\ de-Semantic characters[Email protected] ~]# ls-d test\*LS: Unable to access test*: No file or directory[Ema

, such as log files,[[email protected] ~}# tail-5 file.log//Specify a few lines after viewing the text[[email protected] ~}# tail-n +5 file.log//View the first five lines of the text to the last line(4) More: Split screen view text, you can view text in full screen[Email protected] ~]# more File.log After entering view mode, q exits view, b page UP, F page down. These commands also apply to less, and to the Man command. (more F in the page will skip a

Detailed explanation of ln commands in linux commands (creating soft links and hard links) and ln commands Ln is another important command in linux. Its function is to create a synchronous link for a file in another location, which can be soft link or hard link. Soft links are similar to shortcuts for windows. The following are usage methods and examples. Ln is a