Giới hạn băng thông bằng tc

[phongtvc]

Từ Linux kernel 2.2 đã có thêm tính năng quản lý băng thông bằng tiện ích lệnh tc:

[root@localhost ~]# tc
Usage: tc [ OPTIONS ] OBJECT { COMMAND | help }
       tc [-force] [-OK] -batch filename
where  OBJECT := { qdisc | class | filter | action | monitor }
       OPTIONS := { -s[tatistics] | -d[etails] | -r[aw] | -p[retty] | -b[atch] [filename] | -n[etns] name }

Sau đây mình giới thiệu script để giới hạn 1 IP là 123.30.243.11 kết nối tới Server của mình card mạng eth0:

################################################################
#!/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

# Chọn interface mà IP bên ngoài đang kết nối đến 
IF=eth0             # Interface

# Download limit (in mega bits)
DNLD=100mbit          # DOWNLOAD Limit

# Upload limit (in mega bits)
UPLD=100mbit          # UPLOAD Limit

# IP bạn muốn giới hạn băng thông
IP=123.30.243.11     # 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
##################################################################

Chú ý sửa lựa chọn card mạng, limit up/down là bao nhiêu và IP cần giới hạn băng thông trong script

Cách chạy khá đơn giản:

$chmod 755 tc.bash
$./tc.bash start