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786 lines
32 KiB
XML
786 lines
32 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
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"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
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<refentry>
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||
<refmeta>
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<refentrytitle>shorewall-tcclasses</refentrytitle>
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||
<manvolnum>5</manvolnum>
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<refmiscinfo>Configuration Files</refmiscinfo>
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</refmeta>
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||
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<refnamediv>
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<refname>tcclasses</refname>
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<refpurpose>Shorewall file to define HTB and HFSC classes</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<cmdsynopsis>
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<command>/etc/shorewall[6]/tcclasses</command>
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</cmdsynopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Description</title>
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<para>A note on the <emphasis>rate</emphasis>/bandwidth definitions used
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in this file:</para>
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||
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<itemizedlist>
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||
<listitem>
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<para>don't use a space between the integer value and the unit: 30kbit
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||
is valid while 30 kbit is NOT.</para>
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||
</listitem>
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||
|
||
<listitem>
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||
<para>you can use one of the following units:</para>
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||
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<variablelist>
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||
<varlistentry>
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<term><emphasis role="bold">kpbs</emphasis></term>
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||
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||
<listitem>
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||
<para>Kilobytes per second.</para>
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||
</listitem>
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||
</varlistentry>
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||
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||
<varlistentry>
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||
<term><emphasis role="bold">mbps</emphasis></term>
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||
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||
<listitem>
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||
<para>Megabytes per second.</para>
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||
</listitem>
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||
</varlistentry>
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||
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||
<varlistentry>
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||
<term><emphasis role="bold">kbit</emphasis></term>
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||
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||
<listitem>
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||
<para>Kilobits per second.</para>
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||
</listitem>
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||
</varlistentry>
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||
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||
<varlistentry>
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||
<term><emphasis role="bold">mbit</emphasis></term>
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||
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||
<listitem>
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<para>Megabits per second.</para>
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||
</listitem>
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||
</varlistentry>
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||
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||
<varlistentry>
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||
<term><emphasis role="bold">bps</emphasis> or <emphasis
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||
role="bold">number</emphasis></term>
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||
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||
<listitem>
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||
<para>Bytes per second.</para>
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</listitem>
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</varlistentry>
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||
</variablelist>
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</listitem>
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||
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<listitem>
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<para>if you want the values to be calculated for you depending on the
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output bandwidth setting defined for an interface in tcdevices, you
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can use expressions like the following:</para>
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<variablelist>
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<varlistentry>
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<term>full/3</term>
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<listitem>
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<para>causes the bandwidth to be calculated as 1/3 of the full
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outgoing speed that is defined.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>full*9/10</term>
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||
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<listitem>
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<para>will set this bandwidth to 9/10 of the full
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bandwidth</para>
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</listitem>
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</varlistentry>
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</variablelist>
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<para>Note that in a sub-class (a class that has a specified parent
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class), full refers to the RATE or CEIL of the parent class rather
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than to the OUT-BANDWIDTH of the device.</para>
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||
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<para>DO NOT add a unit to the rate if it is calculated !</para>
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</listitem>
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</itemizedlist>
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<para>The columns in the file are as follows.</para>
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<variablelist>
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<varlistentry>
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<term><emphasis role="bold">INTERFACE</emphasis> -
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<emphasis>interface</emphasis>[[:<emphasis>parent</emphasis>]:<emphasis>class</emphasis>]</term>
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<listitem>
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<para>Name of <emphasis>interface</emphasis>.</para>
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||
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||
<para>You may specify the interface number rather than the interface
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name. If the <emphasis role="bold">classify</emphasis> option is
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given for the interface in <ulink
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url="/manpages/shorewall-tcdevices.html">shorewall-tcdevices</ulink>(5),
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then you must also specify an interface class (an integer that must
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be unique within classes associated with this interface). If the
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classify option is not given, you may still specify a
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<emphasis>class</emphasis> or you may have Shorewall generate a
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class number from the MARK value. Interface numbers and class
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numbers are always assumed to be specified in hex and class number 1
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is reserved as the root class of the queuing discipline.</para>
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<para>You may NOT specify wildcards here, e.g. if you have multiple
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ppp interfaces, you need to put them all in here!</para>
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<para>Please note that you can only use interface names in here that
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have a bandwidth defined in the <ulink
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url="/manpages/shorewall-tcdevices.html">shorewall-tcdevices</ulink>(5)
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file.</para>
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<para>Normally, all classes defined here are sub-classes of a root
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class that is implicitly defined from the entry in <ulink
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url="/manpages/shorewall-tcdevices.html">shorewall-tcdevices</ulink>(5).
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You can establish a class hierarchy by specifying a
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<emphasis>parent</emphasis> class -- the number of a class that you
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have previously defined. The sub-class may borrow unused bandwidth
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from its parent.</para>
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</listitem>
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||
</varlistentry>
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||
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||
<varlistentry>
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<term><emphasis role="bold">MARK</emphasis> -
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{-|<replaceable>value</replaceable>[:<replaceable>priority</replaceable>]}</term>
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<listitem>
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<para>The mark <emphasis>value</emphasis> which is an integer in the
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range 1-255. You set mark values in the <ulink
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url="/manpages/shorewall-mangle.html">shorewall-mangle</ulink>(5)
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file, marking the traffic you want to fit in the classes defined in
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here. You can use the same marks for different interfaces.</para>
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||
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<para>The <replaceable>priority</replaceable>, if specified, is an
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integer in the range 1-65535 and determines the relative order in
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which the tc mark classification filter for this class is to be
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applied to packets being sent on the
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<replaceable>interface</replaceable>. Filters are applied in
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ascending numerical order. If not supplied, the value is derived
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||
from the class priority (PRIORITY column value below):
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||
(<replaceable>class priority</replaceable> << 8) | 20.</para>
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||
</listitem>
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||
</varlistentry>
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||
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||
<varlistentry>
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<term><emphasis role="bold">RATE</emphasis> -
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{-|<emphasis>rate</emphasis>[:<emphasis>dmax</emphasis>[:<emphasis>umax</emphasis>]]}</term>
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||
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<listitem>
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<para>The minimum bandwidth this class should get, when the traffic
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load rises. If the sum of the rates in this column exceeds the
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INTERFACE's OUT-BANDWIDTH, then the OUT-BANDWIDTH limit may not be
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honored. Similarly, if the sum of the rates of sub-classes of a
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||
class exceed the CEIL of the parent class, things don't work
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well.</para>
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||
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<para>When using the HFSC queuing discipline, this column specify
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the real-time (RT) service curve. leaf classes may specify
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<replaceable>dmax</replaceable>, the maximum delay in milliseconds
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||
that the first queued packet for this class should experience. May
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be expressed as an integer, optionally followed by 'ms' with no
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intervening white-space (e.g., 10ms).</para>
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<para>HFSC leaf classes may also specify
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<replaceable>umax</replaceable>, the largest packet expected in this
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class. May be expressed as an integer. The unit of measure is
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<emphasis>bytes</emphasis> and the integer may be optionally
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followed by 'b' with no intervening white-space (e.g., 800b).
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<replaceable>umax</replaceable> may only be given if
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<replaceable>dmax</replaceable> is also given.</para>
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||
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<para>Beginning with Shorewall 4.5.6, HFSC classes may omit this
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||
column (e.g, '-' in the column), provided that an
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<replaceable>lsrate</replaceable> is specified (see CEIL below).
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These rates are used to arbitrate between classes of the same
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||
priority.</para>
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</listitem>
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||
</varlistentry>
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||
<varlistentry>
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||
<term><emphasis role="bold">CEIL</emphasis> -
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||
[<emphasis>lsrate</emphasis>:]<emphasis>rate</emphasis></term>
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||
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||
<listitem>
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||
<para>The maximum bandwidth this class is allowed to use when the
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link is idle. Useful if you have traffic which can get full speed
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||
when more needed services (e.g. ssh) are not used.</para>
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||
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||
<para>You can use the value <emphasis role="bold">full</emphasis> in
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here for setting the maximum bandwidth to the RATE of the parent
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||
class, or the OUT-BANDWIDTH of the device if there is no parent
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||
class.</para>
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||
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||
<para>Beginning with Shorewall 4.5.6, you can also specify an
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<replaceable>lsrate</replaceable> (link sharing rate).</para>
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||
</listitem>
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||
</varlistentry>
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||
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||
<varlistentry>
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||
<term><emphasis role="bold">PRIORITY</emphasis> -
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<emphasis>priority</emphasis></term>
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||
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||
<listitem>
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<para>For HTB:</para>
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||
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||
<blockquote>
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<para>The <emphasis>priority</emphasis> in which classes will be
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serviced by the packet shaping scheduler and also the priority in
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||
which bandwidth in excess of the rate will be given to each
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||
class.</para>
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||
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||
<para>Higher priority classes will experience less delay since
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they are serviced first. Priority values are serviced in ascending
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||
order (e.g. 0 is higher priority than 1).</para>
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||
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||
<para>Classes may be set to the same priority, in which case they
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||
will be serviced as equals.</para>
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||
</blockquote>
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||
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||
<para>For both HTB and HFSC, the <emphasis>priority</emphasis> is
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||
used to calculate the priority of following Shorewall-generated
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classification filters that refer to the class:</para>
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||
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||
<itemizedlist>
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||
<listitem>
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||
<para>Packet MARK</para>
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||
</listitem>
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||
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||
<listitem>
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||
<para><emphasis role="bold">tcp-ack</emphasis> and the <emphasis
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role="bold">tos</emphasis> options (see below)</para>
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||
</listitem>
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||
</itemizedlist>
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||
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||
<para>The rules for classes with lower numeric priorities will
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||
appear before those with higher numeric priorities.</para>
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||
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||
<para>Beginning with Shorewall 4.5.8, the PRIORITY may be omitted
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||
from an HFSC class if you do not use the MARK column or the
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||
<emphasis role="bold">tcp-ack</emphasis> or <emphasis
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||
role="bold">tos</emphasis> options. If you use any of those features
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||
and omit the PRIORITY, then you must specify a
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||
<replaceable>priority</replaceable> along with the MARK or
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||
option.</para>
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||
</listitem>
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||
</varlistentry>
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||
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||
<varlistentry>
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||
<term><emphasis role="bold">OPTIONS</emphasis> (Optional) -
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||
[<emphasis>option</emphasis>[<emphasis
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||
role="bold">,</emphasis><emphasis>option</emphasis>]...]</term>
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||
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||
<listitem>
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||
<para>A comma-separated list of options including the
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||
following:</para>
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||
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||
<variablelist>
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||
<varlistentry>
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||
<term><emphasis role="bold">default</emphasis></term>
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||
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||
<listitem>
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||
<para>This is the default class for that interface where all
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||
traffic should go, that is not classified otherwise.</para>
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||
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||
<para/>
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||
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||
<note>
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||
<para>You must define <emphasis
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||
role="bold">default</emphasis> for exactly one class per
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||
interface.</para>
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||
</note>
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||
</listitem>
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||
</varlistentry>
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||
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||
<varlistentry>
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||
<term><emphasis
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||
role="bold">tos=0x</emphasis><emphasis>value</emphasis>[/0x<emphasis>mask</emphasis>][:<replaceable>priority</replaceable>]
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(mask defaults to 0xff)</term>
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||
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||
<listitem>
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||
<para>This lets you define a classifier for the given
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||
<emphasis>value</emphasis>/<emphasis>mask</emphasis>
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||
combination of the IP packet's TOS/Precedence/DiffSrv octet
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||
(aka the TOS byte).</para>
|
||
|
||
<para>Beginning with Shorewall 4.5.8, the
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||
<replaceable>value/mask</replaceable> may be followed by a
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||
colon (":") and a <replaceable>priority</replaceable>. This
|
||
priority determines the order in which filter rules are
|
||
processed during packet classification. If not specified, the
|
||
value (<replaceable>class priority</replaceable> << 8) |
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||
15) is used.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><emphasis
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||
role="bold">tos-</emphasis><emphasis>tosname</emphasis>[:<replaceable>priority</replaceable>]</term>
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||
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||
<listitem>
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||
<para>Aliases for the following TOS octet value and mask
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||
encodings. TOS encodings of the "TOS byte" have been
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||
deprecated in favor of diffserve classes, but programs like
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||
ssh, rlogin, and ftp still use them.</para>
|
||
|
||
<para>Beginning with Shorewall 4.5.8, the
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||
<replaceable>tos-name</replaceable> may be followed by a colon
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||
(":") and a <replaceable>priority</replaceable>. This priority
|
||
determines the order in which filter rules are processed
|
||
during packet classification. If not specified, the value
|
||
(<replaceable>class priority</replaceable> << 8) | 15)
|
||
is used.</para>
|
||
|
||
<programlisting> <emphasis role="bold">tos-minimize-delay</emphasis> 0x10/0x10
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||
<emphasis role="bold">tos-maximize-throughput</emphasis> 0x08/0x08
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||
<emphasis role="bold">tos-maximize-reliability</emphasis> 0x04/0x04
|
||
<emphasis role="bold">tos-minimize-cost</emphasis> 0x02/0x02
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||
<emphasis role="bold">tos-normal-service</emphasis> 0x00/0x1e</programlisting>
|
||
|
||
<note>
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||
<para>Each of these options is only valid for ONE class per
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||
interface.</para>
|
||
</note>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><emphasis
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||
role="bold">tcp-ack[:<replaceable>priority</replaceable>]</emphasis></term>
|
||
|
||
<listitem>
|
||
<para>If defined, causes a tc filter to be created that puts
|
||
all tcp ack packets on that interface that have a size of
|
||
<=64 Bytes to go in this class. This is useful for speeding
|
||
up downloads. Please note that the size of the ack packets is
|
||
limited to 64 bytes because we want only packets WITHOUT
|
||
payload to match.</para>
|
||
|
||
<para>Beginning with Shorewall 4.5.8, the <emphasis
|
||
role="bold">tcp-ack</emphasis> may be followed by a colon
|
||
(":") and a <replaceable>priority</replaceable>. This priority
|
||
determines the order in which filter rules are processed
|
||
during packet classification. If not specified, the value
|
||
(<replaceable>class priority</replaceable> << 8) | 10)
|
||
is used.</para>
|
||
|
||
<note>
|
||
<para>This option is only valid for ONE class per
|
||
interface.</para>
|
||
</note>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><emphasis
|
||
role="bold">occurs</emphasis>=<emphasis>number</emphasis></term>
|
||
|
||
<listitem>
|
||
<para>Typically used with an IPMARK entry in tcrules. Causes
|
||
the rule to be replicated for a total of
|
||
<emphasis>number</emphasis> rules. Each rule has a
|
||
successively class number and mark value.</para>
|
||
|
||
<para>When 'occurs' is used:</para>
|
||
|
||
<itemizedlist>
|
||
<listitem>
|
||
<para>The associated device may not have the 'classify'
|
||
option.</para>
|
||
</listitem>
|
||
|
||
<listitem>
|
||
<para>The class may not be the default class.</para>
|
||
</listitem>
|
||
|
||
<listitem>
|
||
<para>The class may not have any 'tos=' options (including
|
||
'tcp-ack').</para>
|
||
</listitem>
|
||
|
||
<listitem>
|
||
<para>The class should not specify a MARK value. If one is
|
||
specified, it will be ignored with a warning
|
||
message.</para>
|
||
</listitem>
|
||
</itemizedlist>
|
||
|
||
<para>The 'RATE' and 'CEIL' parameters apply to each instance
|
||
of the class. So the total RATE represented by an entry with
|
||
'occurs' will be the listed RATE multiplied by
|
||
<emphasis>number</emphasis>. For additional information, see
|
||
<ulink
|
||
url="/manpages/shorewall-tcrules.html">shorewall-tcrules</ulink>
|
||
(5).</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>flow=<emphasis>keys</emphasis></term>
|
||
|
||
<listitem>
|
||
<para>Shorewall attaches an SFQ queuing discipline to each
|
||
leaf HTB class. SFQ ensures that each
|
||
<firstterm>flow</firstterm> gets equal access to the
|
||
interface. The default definition of a flow corresponds
|
||
roughly to a Netfilter connection. So if one internal system
|
||
is running BitTorrent, for example, it can have lots of
|
||
'flows' and can thus take up a larger share of the bandwidth
|
||
than a system having only a single active connection. The
|
||
<option>flow</option> classifier (module cls_flow) works
|
||
around this by letting you define what a 'flow' is. The
|
||
classifier must be used carefully or it can block off all
|
||
traffic on an interface! The flow option can be specified for
|
||
an HTB leaf class (one that has no sub-classes). We recommend
|
||
that you use the following:</para>
|
||
|
||
<simplelist>
|
||
<member>Shaping internet-bound traffic:
|
||
flow=nfct-src</member>
|
||
|
||
<member>Shaping traffic bound for your local net:
|
||
flow=dst</member>
|
||
</simplelist>
|
||
|
||
<para>These will cause a 'flow' to consists of the traffic
|
||
to/from each internal system.</para>
|
||
|
||
<para>When more than one key is give, they must be enclosed in
|
||
parenthesis and separated by commas.</para>
|
||
|
||
<para>To see a list of the possible flow keys, run this
|
||
command:</para>
|
||
|
||
<blockquote>
|
||
<para><command>tc filter add flow help</command></para>
|
||
</blockquote>
|
||
|
||
<para>Those that begin with "nfct-" are Netfilter connection
|
||
tracking fields. As shown above, we recommend flow=nfct-src;
|
||
that means that we want to use the source IP address
|
||
<emphasis>before NAT</emphasis> as the key.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>pfifo</term>
|
||
|
||
<listitem>
|
||
<para>When specified for a leaf class, the pfifo queuing
|
||
discipline is applied to the class rather than the sfq queuing
|
||
discipline.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>limit=<emphasis>number</emphasis></term>
|
||
|
||
<listitem>
|
||
<para>Added in Shorewall 4.4.3. When specified for a leaf
|
||
class, determines the maximum number of packets that may be
|
||
queued within the class. The <emphasis>number</emphasis> must
|
||
be > 2 and <=128. If not specified, the value 127 is
|
||
assumed.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>red=(<replaceable>redoption</replaceable>=<replaceable>value</replaceable>,
|
||
...)</term>
|
||
|
||
<listitem>
|
||
<para>Added in Shorewall 4.5.6. When specified on a leaf
|
||
class, causes the class to use the RED (Random Early
|
||
Detection) queuing discipline rather than SFQ. See tc-red (8)
|
||
for additional information.</para>
|
||
|
||
<para>Allowable <replaceable>redoptions</replaceable>
|
||
are:</para>
|
||
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term>min <replaceable>min</replaceable></term>
|
||
|
||
<listitem>
|
||
<para>Average queue size at which marking becomes a
|
||
possibility.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>max <replaceable>max</replaceable></term>
|
||
|
||
<listitem>
|
||
<para>At this average queue size, the marking
|
||
probability is maximal. Must be at least twice
|
||
<replaceable>min</replaceable> to prevent synchronous
|
||
retransmits, higher for low
|
||
<replaceable>min</replaceable>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>probability
|
||
<replaceable>probability</replaceable></term>
|
||
|
||
<listitem>
|
||
<para>Maximum probability for marking, specified as a
|
||
floating point number from 0.0 to 1.0. Suggested values
|
||
are 0.01 or 0.02 (1 or 2%, respectively).</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>limit <replaceable>limit</replaceable></term>
|
||
|
||
<listitem>
|
||
<para>Hard limit on the real (not average) queue size in
|
||
bytes. Further packets are dropped. Should be set higher
|
||
than
|
||
<replaceable>max</replaceable>+<replaceable>burst</replaceable>.
|
||
It is advised to set this a few times higher than
|
||
<replaceable>max</replaceable>. Shorewall requires that
|
||
<replaceable>limit</replaceable> be at least twice
|
||
<replaceable>min</replaceable>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>burst <replaceable>burst</replaceable></term>
|
||
|
||
<listitem>
|
||
<para>Used for determining how fast the average queue
|
||
size is influenced by the real queue size. Larger values
|
||
make the calculation more sluggish, allowing longer
|
||
bursts of traffic before marking starts. Real life
|
||
experiments support the following guide‐line:
|
||
(<replaceable>min</replaceable>+<replaceable>min</replaceable>+<replaceable>max</replaceable>)/(3*<replaceable>avpkt</replaceable>).</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>avpkt <replaceable>avpkt</replaceable></term>
|
||
|
||
<listitem>
|
||
<para>Optional. Specified in bytes. Used with burst to
|
||
determine the time constant for average queue size
|
||
calculations. 1000 is a good value and is the Shorewall
|
||
default.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>bandwidth
|
||
<replaceable>bandwidth</replaceable></term>
|
||
|
||
<listitem>
|
||
<para>Optional. This rate is used for calculating the
|
||
average queue size after some idle time. Should be set
|
||
to the bandwidth of your interface. Does not mean that
|
||
RED will shape for you!</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>ecn</term>
|
||
|
||
<listitem>
|
||
<para>RED can either 'mark' or 'drop'. Explicit
|
||
Congestion Notification allows RED to notify remote
|
||
hosts that their rate exceeds the amount of bandwidth
|
||
available. Non-ECN capable hosts can only be notified by
|
||
dropping a packet. If this parameter is specified,
|
||
packets which indicate that their hosts honor ECN will
|
||
only be marked and not dropped, unless the queue size
|
||
hits <replaceable>limit</replaceable> bytes.
|
||
Recommended.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>fq_codel[=(<replaceable>codeloption</replaceable>=<replaceable>value</replaceable>,
|
||
...)]</term>
|
||
|
||
<listitem>
|
||
<para>Added in Shorewall 4.5.12. When specified for a leaf
|
||
class, causes the class to use the FQ_CODEL (Fair-queuing
|
||
Controlled Delay) queuing discipline rather than SFQ. See
|
||
tc-fq_codel (8) for additional information.</para>
|
||
|
||
<para>Allowable <replaceable>codeloptions</replaceable>
|
||
are:</para>
|
||
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term>limit</term>
|
||
|
||
<listitem>
|
||
<para>hard limit on the real queue size. When this limit
|
||
is reached, incoming packets are dropped. If the value
|
||
is lowered, packets are dropped so that the new limit is
|
||
met. Default is 1000 packets.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>flows</term>
|
||
|
||
<listitem>
|
||
<para>is the number of flows into which the incoming
|
||
packets are classified. Due to the stochastic nature of
|
||
hashing, multiple flows may end up being hashed into the
|
||
same slot. Newer flows have priority over older ones.
|
||
This parameter can be set only at load time since memory
|
||
has to be allocated for the hash table. Default value is
|
||
1024.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>target</term>
|
||
|
||
<listitem>
|
||
<para>is the acceptable minimum standing/persistent
|
||
queue delay. This minimum delay is identified by
|
||
tracking the local minimum queue delay that packets
|
||
experience. Default and recommended value is 5ms.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>interval</term>
|
||
|
||
<listitem>
|
||
<para>is used to ensure that the measured minimum delay
|
||
does not become too stale. The minimum delay must be
|
||
experienced in the last epoch of length interval. It
|
||
should be set on the order of the worst-case RTT through
|
||
the bottleneck to give endpoints sufficient time to
|
||
react. Default value is 100ms.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>quantum</term>
|
||
|
||
<listitem>
|
||
<para>is the number of bytes used as 'deficit' in the
|
||
fair queuing algorithm. Default is set to 1514 bytes
|
||
which corresponds to the Ethernet MTU plus the hardware
|
||
header length of 14 bytes.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term>ecn | noecn</term>
|
||
|
||
<listitem>
|
||
<para>can be used to mark packets instead of dropping
|
||
them. If ecn has been enabled, noecn can be used to turn
|
||
it off and vice-versa. By default, ecn is
|
||
enabled.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
</listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
</listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Examples</title>
|
||
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term>Example 1:</term>
|
||
|
||
<listitem>
|
||
<para>Suppose you are using PPP over Ethernet (DSL) and ppp0 is the
|
||
interface for this. You have 4 classes here, the first you can use
|
||
for voice over IP traffic, the second interactive traffic (e.g.
|
||
ssh/telnet but not scp), the third will be for all unclassified
|
||
traffic, and the forth is for low priority traffic (e.g.
|
||
peer-to-peer).</para>
|
||
|
||
<para>The voice traffic in the first class will be guaranteed a
|
||
minimum of 100kbps and always be serviced first (because of the low
|
||
priority number, giving less delay) and will be granted excess
|
||
bandwidth (up to 180kbps, the class ceiling) first, before any other
|
||
traffic. A single VoIP stream, depending upon codecs, after
|
||
encapsulation, can take up to 80kbps on a PPPoE/DSL link, so we pad
|
||
a little bit just in case. (TOS byte values 0xb8 and 0x68 are
|
||
DiffServ classes EF and AFF3-1 respectively and are often used by
|
||
VOIP devices).</para>
|
||
|
||
<para>Interactive traffic (tos-minimum-delay) and TCP acks (and ICMP
|
||
echo traffic if you use the example in tcrules) and any packet with
|
||
a mark of 2 will be guaranteed 1/4 of the link bandwidth, and may
|
||
extend up to full speed of the link.</para>
|
||
|
||
<para>Unclassified traffic and packets marked as 3 will be
|
||
guaranteed 1/4th of the link bandwidth, and may extend to the full
|
||
speed of the link.</para>
|
||
|
||
<para>Packets marked with 4 will be treated as low priority packets.
|
||
(The tcrules example marks p2p traffic as such.) If the link is
|
||
congested, they're only guaranteed 1/8th of the speed, and even if
|
||
the link is empty, can only expand to 80% of link bandwidth just as
|
||
a precaution in case there are upstream queues we didn't account
|
||
for. This is the last class to get additional bandwidth and the last
|
||
to get serviced by the scheduler because of the low priority.</para>
|
||
|
||
<programlisting> #INTERFACE MARK RATE CEIL PRIORITY OPTIONS
|
||
ppp0 1 100kbit 180kbit 1 tos=0x68/0xfc,tos=0xb8/0xfc
|
||
ppp0 2 full/4 full 2 tcp-ack,tos-minimize-delay
|
||
ppp0 3 full/4 full 3 default
|
||
ppp0 4 full/8 full*8/10 4</programlisting>
|
||
</listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>FILES</title>
|
||
|
||
<para>/etc/shorewall/tcclasses</para>
|
||
|
||
<para>/etc/shorewall6/tcclasses</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>See ALSO</title>
|
||
|
||
<para><ulink
|
||
url="/traffic_shaping.htm">http://www.shorewall.net/traffic_shaping.htm</ulink></para>
|
||
|
||
<para><ulink
|
||
url="/configuration_file_basics.htm#Pairs">http://www.shorewall.net/configuration_file_basics.htm#Pairs</ulink></para>
|
||
|
||
<para>tc-hfsc(7)</para>
|
||
|
||
<para>tc-red(8)</para>
|
||
|
||
<para>shorewall(8)</para>
|
||
</refsect1>
|
||
</refentry>
|