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Basically I wanted to change the bandwidth after every 10 seconds using tc. So how to do that thing in tc.

This is my script.

!/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

Help me to make the necessary changes in the script to resolve my problem.

A.B
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    I can just tell that you are not handling download speed: the qdisc is acting on *egress* only and `match ip dst` will never match since the destination in an outgoing packet on $IF is most likely not $IP. You'd probably have to use an IFB interface to handle incoming. See this script as example: https://github.com/magnific0/wondershaper/blob/b0663cb6c9000893434b3cddf0cae50a33941926/wondershaper#L243 . (Beside this, I don't know how to address your problem.) – A.B May 25 '21 at 18:54
  • I got that point src is the second session only it is not the incoming traffic .Consider it like that way. Basically I wanted to change the bandwidth after every 10 seconds. That logic i wanted to implement in this script – Abhishek Chapla May 25 '21 at 18:59

0 Answers0