Hi,
I''ve read ADSL-Bandwidth-Management-HOWTO
http://www.tldp.org/HOWTO/ADSL-Bandwidth-Management-HOWTO/implementation.htm
l#AEN166
and I''ve a doubt from script:
[ ... ]
# DNS name resolution (small packets)
iptables -t mangle -A MYSHAPER-OUT -p udp -j MARK --set-mark 21
[ ... ]
That is a bug ?
I think that " DNS name resolution (small packets) " is better
match
with:
# DNS name resolution (small packets)
iptables -t mangle -A MYSHAPER-OUT -p udp --dport 53 -j MARK --set-mark 21
iptables -t mangle -A MYSHAPER-OUT -p tcp --dport 53 -j MARK --set-mark 21
ORIGINAL AND COMPLETE SCRIPT IS HERE:
#!/bin/bash
#
# myshaper - DSL/Cable modem outbound traffic shaper and prioritizer.
# Based on the ADSL/Cable wondershaper (www.lartc.org)
#
# Written by Dan Singletary (8/7/02)
#
# NOTE!! - This script assumes your kernel has been patched with the
# appropriate HTB queue and IMQ patches available here:
# (subnote: future kernels may not require patching)
#
# http://luxik.cdi.cz/~devik/qos/htb/
# http://luxik.cdi.cz/~patrick/imq/
#
# Configuration options for myshaper:
# DEV - set to ethX that connects to DSL/Cable Modem
# RATEUP - set this to slightly lower than your
# outbound bandwidth on the DSL/Cable Modem.
# I have a 1500/128 DSL line and setting
# RATEUP=90 works well for my 128kbps upstream.
# However, your mileage may vary.
# RATEDN - set this to slightly lower than your
# inbound bandwidth on the DSL/Cable Modem.
#
#
# Theory on using imq to "shape" inbound traffic:
#
# It''s impossible to directly limit the rate of data that will
# be sent to you by other hosts on the internet. In order to shape
# the inbound traffic rate, we have to rely on the congestion avoidance
# algorithms in TCP. Because of this, WE CAN ONLY ATTEMPT TO SHAPE
# INBOUND TRAFFIC ON TCP CONNECTIONS. This means that any traffic that
# is not tcp should be placed in the high-prio class, since dropping
# a non-tcp packet will most likely result in a retransmit which will
# do nothing but unnecessarily consume bandwidth.
# We attempt to shape inbound TCP traffic by dropping tcp packets
# when they overflow the HTB queue which will only pass them on at
# a certain rate (RATEDN) which is slightly lower than the actual
# capability of the inbound device. By dropping TCP packets that
# are over-rate, we are simulating the same packets getting dropped
# due to a queue-overflow on our ISP''s side. The advantage of this
# is that our ISP''s queue will never fill because TCP will slow
it''s
# transmission rate in response to the dropped packets in the assumption
# that it has filled the ISP''s queue, when in reality it has not.
# The advantage of using a priority-based queuing discipline is
# that we can specifically choose NOT to drop certain types of packets
# that we place in the higher priority buckets (ssh, telnet, etc). This
# is because packets will always be dequeued from the lowest priority class
# with the stipulation that packets will still be dequeued from every
# class fairly at a minimum rate (in this script, each bucket will deliver
# at least it''s fair share of 1/7 of the bandwidth).
#
# Reiterating main points:
# * Dropping a tcp packet on a connection will lead to a slower rate
# of reception for that connection due to the congestion avoidance
algorithm.
# * We gain nothing from dropping non-TCP packets. In fact, if they
# were important they would probably be retransmitted anyways so we want
to
# try to never drop these packets. This means that saturated TCP
connections
# will not negatively effect protocols that don''t have a built-in
retransmit like TCP.
# * Slowing down incoming TCP connections such that the total inbound rate
is less
# than the true capability of the device (ADSL/Cable Modem) SHOULD
result in little
# to no packets being queued on the ISP''s side (DSLAM, cable
concentrator, etc). Since
# these ISP queues have been observed to queue 4 seconds of data at
1500Kbps or 6 megabits
# of data, having no packets queued there will mean lower latency.
#
# Caveats (questions posed before testing):
# * Will limiting inbound traffic in this fashion result in poor bulk TCP
performance?
# - Preliminary answer is no! Seems that by prioritizing ACK packets
(small <64b)
# we maximize throughput by not wasting bandwidth on retransmitted
packets
# that we already have.
#
# NOTE: The following configuration works well for my
# setup: 1.5M/128K ADSL via Pacific Bell Internet (SBC Global Services)
DEV=eth0
RATEUP=90
RATEDN=700 # Note that this is significantly lower than the capacity of
1500.
# Because of this, you may not want to bother limiting inbound
traffic
# until a better implementation such as TCP window manipulation
can be used.
#
# End Configuration Options
#
if [ "$1" = "status" ]
then
echo "[qdisc]"
tc -s qdisc show dev $DEV
tc -s qdisc show dev imq0
echo "[class]"
tc -s class show dev $DEV
tc -s class show dev imq0
echo "[filter]"
tc -s filter show dev $DEV
tc -s filter show dev imq0
echo "[iptables]"
iptables -t mangle -L MYSHAPER-OUT -v -x 2> /dev/null
iptables -t mangle -L MYSHAPER-IN -v -x 2> /dev/null
exit
fi
# Reset everything to a known state (cleared)
tc qdisc del dev $DEV root 2> /dev/null > /dev/null
tc qdisc del dev imq0 root 2> /dev/null > /dev/null
iptables -t mangle -D POSTROUTING -o $DEV -j MYSHAPER-OUT 2> /dev/null >
/dev/null
iptables -t mangle -F MYSHAPER-OUT 2> /dev/null > /dev/null
iptables -t mangle -X MYSHAPER-OUT 2> /dev/null > /dev/null
iptables -t mangle -D PREROUTING -i $DEV -j MYSHAPER-IN 2> /dev/null >
/dev/null
iptables -t mangle -F MYSHAPER-IN 2> /dev/null > /dev/null
iptables -t mangle -X MYSHAPER-IN 2> /dev/null > /dev/null
ip link set imq0 down 2> /dev/null > /dev/null
rmmod imq 2> /dev/null > /dev/null
if [ "$1" = "stop" ]
then
echo "Shaping removed on $DEV."
exit
fi
###########################################################
#
# Outbound Shaping (limits total bandwidth to RATEUP)
# set queue size to give latency of about 2 seconds on low-prio packets
ip link set dev $DEV qlen 30
# changes mtu on the outbound device. Lowering the mtu will result
# in lower latency but will also cause slightly lower throughput due
# to IP and TCP protocol overhead.
ip link set dev $DEV mtu 1000
# add HTB root qdisc
tc qdisc add dev $DEV root handle 1: htb default 26
# add main rate limit classes
tc class add dev $DEV parent 1: classid 1:1 htb rate ${RATEUP}kbit
# add leaf classes - We grant each class at LEAST it''s "fair
share" of
bandwidth.
# this way no class will ever be starved by another
class. Each
# class is also permitted to consume all of the available
bandwidth
# if no other classes are in use.
tc class add dev $DEV parent 1:1 classid 1:20 htb rate $[$RATEUP/7]kbit ceil
${RATEUP}kbit prio 0
tc class add dev $DEV parent 1:1 classid 1:21 htb rate $[$RATEUP/7]kbit ceil
${RATEUP}kbit prio 1
tc class add dev $DEV parent 1:1 classid 1:22 htb rate $[$RATEUP/7]kbit ceil
${RATEUP}kbit prio 2
tc class add dev $DEV parent 1:1 classid 1:23 htb rate $[$RATEUP/7]kbit ceil
${RATEUP}kbit prio 3
tc class add dev $DEV parent 1:1 classid 1:24 htb rate $[$RATEUP/7]kbit ceil
${RATEUP}kbit prio 4
tc class add dev $DEV parent 1:1 classid 1:25 htb rate $[$RATEUP/7]kbit ceil
${RATEUP}kbit prio 5
tc class add dev $DEV parent 1:1 classid 1:26 htb rate $[$RATEUP/7]kbit ceil
${RATEUP}kbit prio 6
# attach qdisc to leaf classes - here we at SFQ to each priority class. SFQ
insures that
# within each class connections will be
treated (almost) fairly.
tc qdisc add dev $DEV parent 1:20 handle 20: sfq perturb 10
tc qdisc add dev $DEV parent 1:21 handle 21: sfq perturb 10
tc qdisc add dev $DEV parent 1:22 handle 22: sfq perturb 10
tc qdisc add dev $DEV parent 1:23 handle 23: sfq perturb 10
tc qdisc add dev $DEV parent 1:24 handle 24: sfq perturb 10
tc qdisc add dev $DEV parent 1:25 handle 25: sfq perturb 10
tc qdisc add dev $DEV parent 1:26 handle 26: sfq perturb 10
# filter traffic into classes by fwmark - here we direct traffic into
priority class according to
# the fwmark set on the packet (we
set fwmark with iptables
# later). Note that above
we''ve set
the default priority
# class to 1:26 so unmarked packets
(or packets marked with
# unfamiliar IDs) will be defaulted
to the lowest priority
# class.
tc filter add dev $DEV parent 1:0 prio 0 protocol ip handle 20 fw flowid
1:20
tc filter add dev $DEV parent 1:0 prio 0 protocol ip handle 21 fw flowid
1:21
tc filter add dev $DEV parent 1:0 prio 0 protocol ip handle 22 fw flowid
1:22
tc filter add dev $DEV parent 1:0 prio 0 protocol ip handle 23 fw flowid
1:23
tc filter add dev $DEV parent 1:0 prio 0 protocol ip handle 24 fw flowid
1:24
tc filter add dev $DEV parent 1:0 prio 0 protocol ip handle 25 fw flowid
1:25
tc filter add dev $DEV parent 1:0 prio 0 protocol ip handle 26 fw flowid
1:26
# add MYSHAPER-OUT chain to the mangle table in iptables - this sets up the
table we''ll use
# to filter and mark
packets.
iptables -t mangle -N MYSHAPER-OUT
iptables -t mangle -I POSTROUTING -o $DEV -j MYSHAPER-OUT
# add fwmark entries to classify different types of traffic - Set fwmark
from 20-26 according to
# desired class.
20 is highest prio.
iptables -t mangle -A MYSHAPER-OUT -p tcp --sport 0:1024 -j MARK --set-mark
23 # Default for low port traffic
iptables -t mangle -A MYSHAPER-OUT -p tcp --dport 0:1024 -j MARK --set-mark
23 # ""
iptables -t mangle -A MYSHAPER-OUT -p tcp --dport 20 -j MARK --set-mark 26
# ftp-data port, low prio
iptables -t mangle -A MYSHAPER-OUT -p tcp --dport 5190 -j MARK --set-mark 23
# aol instant messenger
iptables -t mangle -A MYSHAPER-OUT -p icmp -j MARK --set-mark 20
# ICMP (ping) - high prio, impress friends
iptables -t mangle -A MYSHAPER-OUT -p udp -j MARK --set-mark 21
# DNS name resolution (small packets)
iptables -t mangle -A MYSHAPER-OUT -p tcp --dport ssh -j MARK --set-mark 22
# secure shell
iptables -t mangle -A MYSHAPER-OUT -p tcp --sport ssh -j MARK --set-mark 22
# secure shell
iptables -t mangle -A MYSHAPER-OUT -p tcp --dport telnet -j MARK --set-mark
22 # telnet (ew...)
iptables -t mangle -A MYSHAPER-OUT -p tcp --sport telnet -j MARK --set-mark
22 # telnet (ew...)
iptables -t mangle -A MYSHAPER-OUT -p ipv6-crypt -j MARK --set-mark 24
# IPSec - we don''t know what the payload is though...
iptables -t mangle -A MYSHAPER-OUT -p tcp --sport http -j MARK --set-mark 25
# Local web server
iptables -t mangle -A MYSHAPER-OUT -p tcp -m length --length :64 -j
MARK --set-mark 21 # small packets (probably just ACKs)
iptables -t mangle -A MYSHAPER-OUT -m mark --mark 0 -j MARK --set-mark 26
# redundant- mark any unmarked packets as 26 (low prio)
# Done with outbound shaping
#
####################################################
echo "Outbound shaping added to $DEV. Rate: ${RATEUP}Kbit/sec."
# uncomment following line if you only want upstream shaping.
# exit
####################################################
#
# Inbound Shaping (limits total bandwidth to RATEDN)
# make sure imq module is loaded
modprobe imq numdevs=1
ip link set imq0 up
# add qdisc - default low-prio class 1:21
tc qdisc add dev imq0 handle 1: root htb default 21
# add main rate limit classes
tc class add dev imq0 parent 1: classid 1:1 htb rate ${RATEDN}kbit
# add leaf classes - TCP traffic in 21, non TCP traffic in 20
#
tc class add dev imq0 parent 1:1 classid 1:20 htb rate $[$RATEDN/2]kbit ceil
${RATEDN}kbit prio 0
tc class add dev imq0 parent 1:1 classid 1:21 htb rate $[$RATEDN/2]kbit ceil
${RATEDN}kbit prio 1
# attach qdisc to leaf classes - here we at SFQ to each priority class. SFQ
insures that
# within each class connections will be
treated (almost) fairly.
tc qdisc add dev imq0 parent 1:20 handle 20: sfq perturb 10
tc qdisc add dev imq0 parent 1:21 handle 21: red limit 1000000 min 5000 max
100000 avpkt 1000 burst 50
# filter traffic into classes by fwmark - here we direct traffic into
priority class according to
# the fwmark set on the packet (we
set fwmark with iptables
# later). Note that above
we''ve set
the default priority
# class to 1:26 so unmarked packets
(or packets marked with
# unfamiliar IDs) will be defaulted
to the lowest priority
# class.
tc filter add dev imq0 parent 1:0 prio 0 protocol ip handle 20 fw flowid
1:20
tc filter add dev imq0 parent 1:0 prio 0 protocol ip handle 21 fw flowid
1:21
# add MYSHAPER-IN chain to the mangle table in iptables - this sets up the
table we''ll use
# to filter and mark
packets.
iptables -t mangle -N MYSHAPER-IN
iptables -t mangle -I PREROUTING -i $DEV -j MYSHAPER-IN
# add fwmark entries to classify different types of traffic - Set fwmark
from 20-26 according to
# desired class.
20 is highest prio.
iptables -t mangle -A MYSHAPER-IN -p ! tcp -j MARK --set-mark 20
# Set non-tcp packets to highest priority
iptables -t mangle -A MYSHAPER-IN -p tcp -m length --length :64 -j
MARK --set-mark 20 # short TCP packets are probably ACKs
iptables -t mangle -A MYSHAPER-IN -p tcp --dport ssh -j MARK --set-mark 20
# secure shell
iptables -t mangle -A MYSHAPER-IN -p tcp --sport ssh -j MARK --set-mark 20
# secure shell
iptables -t mangle -A MYSHAPER-IN -p tcp --dport telnet -j MARK --set-mark
20 # telnet (ew...)
iptables -t mangle -A MYSHAPER-IN -p tcp --sport telnet -j MARK --set-mark
20 # telnet (ew...)
iptables -t mangle -A MYSHAPER-IN -m mark --mark 0 -j MARK --set-mark 21
# redundant- mark any unmarked packets as 26 (low prio)
# finally, instruct these packets to go through the imq0 we set up above
iptables -t mangle -A MYSHAPER-IN -j IMQ
# Done with inbound shaping
#
####################################################
echo "Inbound shaping added to $DEV. Rate: ${RATEDN}Kbit/sec."
--
Andres Gregori
Linux Support Services
linux@dimensionip.com.ar
291 15 4041973
