linux环境下利用tc限制两台服务器间的网速延时

1、简介

http://www.iplocation.net/tools/traffic-control.php

ts命令功能很强，同时也好难理解和使用，脚本只要设置一下目标ip和需要限制的速率。

ip命令可以进行简写： ip l == ip link list ip a == ip address show ip r == ip route show

#!/bin/bash
#
#  tc uses the following units when passed as a parameter.
#  kbps: Kilobytes per second
#  mbps: Megabytes per second
#  kbit: Kilobits per second
#  mbit: Megabits per second
#  bps: Bytes per second
#       Amounts of data can be specified in:
#       kb or k: Kilobytes
#       mb or m: Megabytes
#       mbit: Megabits
#       kbit: Kilobits
#  To get the byte figure from bits, divide the number by 8 bit
#

#
# Name of the traffic control command.
TC=/sbin/tc

# The network interface we're planning on limiting bandwidth.
IF=eth0             # Interface

# Download limit (in mega bits)
DNLD=1mbit          # DOWNLOAD Limit

# Upload limit (in mega bits)
UPLD=1mbit          # UPLOAD Limit

# IP address of the machine we are controlling
IP=216.3.128.12     # Host IP

# Filter options for limiting the intended interface.
U32="$TC filter add dev $IF protocol ip parent 1:0 prio 1 u32"

start() {

# We'll use Hierarchical Token Bucket (HTB) to shape bandwidth.
# For detailed configuration options, please consult Linux man
# page.

    $TC qdisc add dev $IF root handle 1: htb default 30
    $TC class add dev $IF parent 1: classid 1:1 htb rate $DNLD
    $TC class add dev $IF parent 1: classid 1:2 htb rate $UPLD
    $U32 match ip dst $IP/32 flowid 1:1
    $U32 match ip src $IP/32 flowid 1:2

# The first line creates the root qdisc, and the next two lines
# create two child qdisc that are to be used to shape download
# and upload bandwidth.
#
# The 4th and 5th line creates the filter to match the interface.
# The 'dst' IP address is used to limit download speed, and the
# 'src' IP address is used to limit upload speed.

}

stop() {

# Stop the bandwidth shaping.
    $TC qdisc del dev $IF root

}

restart() {

# Self-explanatory.
    stop
    sleep 1
    start

}

show() {

# Display status of traffic control status.
    $TC -s qdisc ls dev $IF

}

case "$1" in

  start)

    echo -n "Starting bandwidth shaping: "
    start
    echo "done"
    ;;

  stop)

    echo -n "Stopping bandwidth shaping: "
    stop
    echo "done"
    ;;

  restart)

    echo -n "Restarting bandwidth shaping: "
    restart
    echo "done"
    ;;

  show)

    echo "Bandwidth shaping status for $IF:"
    show
    echo ""
    ;;

  *)

    pwd=$(pwd)
    echo "Usage: tc.bash {start|stop|restart|show}"
    ;;

esac

exit 0

2、当遇到网络存在网络延迟时

（1）首先查看网卡名：ip addr | grep -B2 10.70 | awk '{print $2}' | head -n 1 | sed s/://g 很奇怪，最终居然是yyds的eth0。

（2）查看网卡eth0的流量配置 tc qdisc show dev eth0

执行：tc qdisc show dev eth0

qdisc netem 8001: root refcnt 9 limit 1000 delay 100.0ms  10.0ms

直接找到原因，存在网络延迟规则。

（3）删除所有规则 tc qdisc del dev eth4 root 执行之后再次查看流量配置

执行：tc qdisc show dev eth0

qdisc mq 0: root
qdisc pfifo_fast 0: parent :8 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :7 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :6 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :5 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :4 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :3 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :2 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :1 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1

（4）然鹅又被人增加上了 tc qdisc add dev eth0 root netem delay 100ms 10ms 想使用过滤器进行过滤，居然会失败。

3、一次给指定ip增加延迟

把ip修改成指定物理机ip即可，中间可能出现当前主机网口不是eth0。支持多个ip指定。

查看网卡 eth0 的流控的配置 (qdisc 表示排队规则 queueing discipline)
tc qdisc show dev eth0

设置指定IP的延迟和丢包
tc qdisc add dev eth0 root handle 1: prio

限制带宽, 延迟, 丢包
tc filter add dev eth0 parent 1: protocol ip prio 16 u32 match ip dst 123.2.3.6 flowid 1:1
tc filter add dev eth0 parent 1: protocol ip prio 16 u32 match ip dst 223.22.23.26 flowid 1:1
tc qdisc add dev eth0 parent 1:1 handle 10: netem delay 50ms loss 1%

修改规则
tc qdisc change dev eth0 parent 1:1 handle 10: netem delay 150ms loss 5%

删除所有规则
tc qdisc del dev eth4 root

5%丢包已经很严重了，1%一般即可。

4、tc命令包装器tcconfig

使其更容易设置到network-interface/Docker-container(veth)的网络带宽/延迟/数据包丢失/数据包损坏等的流量控制。

tcconfig是一个tc命令包装器。轻松设置网络bandwidth/latency/packet-loss/packet-corruption/etc的流量控制。给network-interface/Docker-container(veth）。

Set traffic control（tcset命令） Delete traffic control（tcdel命令） 显示流量控制配置（tcshow命令）以获取更多信息

• 网络带宽速率[G/M/K bps]
• 网络延迟[microseconds/milliseconds/seconds/minutes]
• 丢包率[%]
• 数据包损坏率[%]
• 数据包重复率[%]
• 数据包重排序率[%]

https://www.5axxw.com/wiki/content/ztvxjf

tc自 linux2.2内核以后逐渐被加在了内核里，成为linux服务器本身就能提供的一种服务。 个人觉得还是学好使用tc吧。