.TH TC 8 "16 December 2001" "iproute2" "Linux"

.SH NAME

tc \- show / manipulate traffic control settings

.SH SYNOPSIS

.B tc

.RI "[ " OPTIONS " ]"

.B qdisc [ add | change | replace | link | delete ] dev

\fIDEV\fR

.B

[ parent

\fIqdisc-id\fR

.B | root ]

.B [ handle

\fIqdisc-id\fR ]

.B [ ingress_block

\fIBLOCK_INDEX\fR ]

.B [ egress_block

\fIBLOCK_INDEX\fR ] qdisc

[ qdisc specific parameters ]

.P

.B tc

.RI "[ " OPTIONS " ]"

.B class [ add | change | replace | delete ] dev

\fIDEV\fR

.B parent

\fIqdisc-id\fR

.B [ classid

\fIclass-id\fR ] qdisc

[ qdisc specific parameters ]

.P

.B tc

.RI "[ " OPTIONS " ]"

.B filter [ add | change | replace | delete | get ] dev

\fIDEV\fR

.B [ parent

\fIqdisc-id\fR

.B | root ] [ handle \fIfilter-id\fR ]

.B protocol

\fIprotocol\fR

.B prio

\fIpriority\fR filtertype

[ filtertype specific parameters ]

.B flowid

\fIflow-id\fR

.B tc

.RI "[ " OPTIONS " ]"

.B filter [ add | change | replace | delete | get ] block

\fIBLOCK_INDEX\fR

.B [ handle \fIfilter-id\fR ]

.B protocol

\fIprotocol\fR

.B prio

\fIpriority\fR filtertype

[ filtertype specific parameters ]

.B flowid

\fIflow-id\fR

.B tc

.RI "[ " OPTIONS " ]"

.B chain [ add | delete | get ] dev

\fIDEV\fR

.B [ parent

\fIqdisc-id\fR

.B | root ]\fR filtertype

[ filtertype specific parameters ]

.B tc

.RI "[ " OPTIONS " ]"

.B chain [ add | delete | get ] block

\fIBLOCK_INDEX\fR filtertype

[ filtertype specific parameters ]

.B tc

.RI "[ " OPTIONS " ]"

.RI "[ " FORMAT " ]"

.B qdisc { show | list } [ dev

\fIDEV\fR

.B ] [ root | ingress | handle

\fIQHANDLE\fR

.B | parent

\fICLASSID\fR

.B ] [ invisible ]

.P

.B tc

.RI "[ " OPTIONS " ]"

.RI "[ " FORMAT " ]"

.B class show dev

\fIDEV\fR

.P

.B tc

.RI "[ " OPTIONS " ]"

.B filter show dev

\fIDEV\fR

.P

.B tc

.RI "[ " OPTIONS " ]"

.B filter show block

\fIBLOCK_INDEX\fR

.P

.B tc

.RI "[ " OPTIONS " ]"

.B chain show dev

\fIDEV\fR

.P

.B tc

.RI "[ " OPTIONS " ]"

.B chain show block

\fIBLOCK_INDEX\fR

.P

.B tc

.RI "[ " OPTIONS " ]"

.B monitor [ file

\fIFILENAME\fR

.B ]

.P

.ti 8

.IR OPTIONS " := {"

\fB[ -force ] -b\fR[\fIatch\fR] \fB[ filename ] \fR|

\fB[ \fB-n\fR[\fIetns\fR] name \fB] \fR|

\fB[ \fB-N\fR[\fIumeric\fR] \fB] \fR|

\fB[ \fB-nm \fR| \fB-nam\fR[\fIes\fR] \fB] \fR|

\fB[ \fR{ \fB-cf \fR| \fB-c\fR[\fIonf\fR] \fR} \fB[ filename ] \fB] \fR

\fB[ -t\fR[imestamp\fR] \fB\] \fR| \fB[ -t\fR[short\fR] \fR| \fB[

-o\fR[neline\fR] \fB]\fR }

.ti 8

.IR FORMAT " := {"

\fB\-s\fR[\fItatistics\fR] |

\fB\-d\fR[\fIetails\fR] |

\fB\-r\fR[\fIaw\fR] |

\fB\-i\fR[\fIec\fR] |

\fB\-g\fR[\fIraph\fR] |

\fB\-j\fR[\fIjson\fR] |

\fB\-p\fR[\fIretty\fR] |

\fB\-col\fR[\fIor\fR] }

.SH DESCRIPTION

.B Tc

is used to configure Traffic Control in the Linux kernel. Traffic Control consists

of the following:

.TP

SHAPING

When traffic is shaped, its rate of transmission is under control. Shaping may

be more than lowering the available bandwidth - it is also used to smooth out

bursts in traffic for better network behaviour. Shaping occurs on egress.

.TP

SCHEDULING

By scheduling the transmission of packets it is possible to improve interactivity

for traffic that needs it while still guaranteeing bandwidth to bulk transfers. Reordering

is also called prioritizing, and happens only on egress.

.TP

POLICING

Whereas shaping deals with transmission of traffic, policing pertains to traffic

arriving. Policing thus occurs on ingress.

.TP

DROPPING

Traffic exceeding a set bandwidth may also be dropped forthwith, both on

ingress and on egress.

.P

Processing of traffic is controlled by three kinds of objects: qdiscs,

classes and filters.

.SH QDISCS

.B qdisc

is short for 'queueing discipline' and it is elementary to

understanding traffic control. Whenever the kernel needs to send a

packet to an interface, it is

.B enqueued

to the qdisc configured for that interface. Immediately afterwards, the kernel

tries to get as many packets as possible from the qdisc, for giving them

to the network adaptor driver.

A simple QDISC is the 'pfifo' one, which does no processing at all and is a pure

First In, First Out queue. It does however store traffic when the network interface

can't handle it momentarily.

.SH CLASSES

Some qdiscs can contain classes, which contain further qdiscs - traffic may

then be enqueued in any of the inner qdiscs, which are within the

.B classes.

When the kernel tries to dequeue a packet from such a

.B classful qdisc

it can come from any of the classes. A qdisc may for example prioritize

certain kinds of traffic by trying to dequeue from certain classes

before others.

.SH FILTERS

A

.B filter

is used by a classful qdisc to determine in which class a packet will

be enqueued. Whenever traffic arrives at a class with subclasses, it needs

to be classified. Various methods may be employed to do so, one of these

are the filters. All filters attached to the class are called, until one of

them returns with a verdict. If no verdict was made, other criteria may be

available. This differs per qdisc.

It is important to notice that filters reside

.B within

qdiscs - they are not masters of what happens.

The available filters are:

.TP

basic

Filter packets based on an ematch expression. See

.BR tc-ematch (8)

for details.

.TP

bpf

Filter packets using (e)BPF, see

.BR tc-bpf (8)

for details.

.TP

cgroup

Filter packets based on the control group of their process. See

. BR tc-cgroup (8)

for details.

.TP

flow, flower

Flow-based classifiers, filtering packets based on their flow (identified by selectable keys). See

.BR tc-flow "(8) and"

.BR tc-flower (8)

for details.

.TP

fw

Filter based on fwmark. Directly maps fwmark value to traffic class. See

.BR tc-fw (8).

.TP

route

Filter packets based on routing table. See

.BR tc-route (8)

for details.

.TP

rsvp

Match Resource Reservation Protocol (RSVP) packets.

.TP

tcindex

Filter packets based on traffic control index. See

.BR tc-tcindex (8).

.TP

u32

Generic filtering on arbitrary packet data, assisted by syntax to abstract common operations. See

.BR tc-u32 (8)

for details.

.TP

matchall

Traffic control filter that matches every packet. See

.BR tc-matchall (8)

for details.

.SH QEVENTS

Qdiscs may invoke user-configured actions when certain interesting events

take place in the qdisc. Each qevent can either be unused, or can have a

block attached to it. To this block are then attached filters using the "tc

block BLOCK_IDX" syntax. The block is executed when the qevent associated

with the attachment point takes place. For example, packet could be

dropped, or delayed, etc., depending on the qdisc and the qevent in

question.

For example:

.PP

.RS

tc qdisc add dev eth0 root handle 1: red limit 500K avpkt 1K \\

   qevent early_drop block 10

.RE

.RS

tc filter add block 10 matchall action mirred egress mirror dev eth1

.RE

.SH CLASSLESS QDISCS

The classless qdiscs are:

.TP

choke

CHOKe (CHOose and Keep for responsive flows, CHOose and Kill for unresponsive

flows) is a classless qdisc designed to both identify and penalize flows that

monopolize the queue. CHOKe is a variation of RED, and the configuration is

similar to RED.

.TP

codel

CoDel (pronounced "coddle") is an adaptive "no-knobs" active queue management

algorithm (AQM) scheme that was developed to address the shortcomings of

RED and its variants.

.TP

[p|b]fifo

Simplest usable qdisc, pure First In, First Out behaviour. Limited in

packets or in bytes.

.TP

fq

Fair Queue Scheduler realises TCP pacing and scales to millions of concurrent

flows per qdisc.

.TP

fq_codel

Fair Queuing Controlled Delay is queuing discipline that combines Fair

Queuing with the CoDel AQM scheme. FQ_Codel uses a stochastic model to classify

incoming packets into different flows and is used to provide a fair share of the

bandwidth to all the flows using the queue. Each such flow is managed by the

CoDel queuing discipline. Reordering within a flow is avoided since Codel

internally uses a FIFO queue.

.TP

fq_pie

FQ-PIE (Flow Queuing with Proportional Integral controller Enhanced) is a

queuing discipline that combines Flow Queuing with the PIE AQM scheme. FQ-PIE

uses a Jenkins hash function to classify incoming packets into different flows

and is used to provide a fair share of the bandwidth to all the flows using the

qdisc. Each such flow is managed by the PIE algorithm.

.TP

gred

Generalized Random Early Detection combines multiple RED queues in order to

achieve multiple drop priorities. This is required to realize Assured

Forwarding (RFC 2597).

.TP

hhf

Heavy-Hitter Filter differentiates between small flows and the opposite,

heavy-hitters. The goal is to catch the heavy-hitters and move them to a

separate queue with less priority so that bulk traffic does not affect the

latency of critical traffic.

.TP

ingress

This is a special qdisc as it applies to incoming traffic on an interface, allowing for it to be filtered and policed.

.TP

mqprio

The Multiqueue Priority Qdisc is a simple queuing discipline that allows

mapping traffic flows to hardware queue ranges using priorities and a

configurable priority to traffic class mapping. A traffic class in this context

is a set of contiguous qdisc classes which map 1:1 to a set of hardware exposed

queues.

.TP

multiq

Multiqueue is a qdisc optimized for devices with multiple Tx queues. It has

been added for hardware that wishes to avoid head-of-line blocking.  It will

cycle though the bands and verify that the hardware queue associated with the

band is not stopped prior to dequeuing a packet.

.TP

netem

Network Emulator is an enhancement of the Linux traffic control facilities that

allow to add delay, packet loss, duplication and more other characteristics to

packets outgoing from a selected network interface.

.TP

pfifo_fast

Standard qdisc for 'Advanced Router' enabled kernels. Consists of a three-band

queue which honors Type of Service flags, as well as the priority that may be

assigned to a packet.

.TP

pie

Proportional Integral controller-Enhanced (PIE) is a control theoretic active

queue management scheme. It is based on the proportional integral controller but

aims to control delay.

.TP

red

Random Early Detection simulates physical congestion by randomly dropping

packets when nearing configured bandwidth allocation. Well suited to very

large bandwidth applications.

.TP

rr

Round-Robin qdisc with support for multiqueue network devices. Removed from

Linux since kernel version 2.6.27.

.TP

sfb

Stochastic Fair Blue is a classless qdisc to manage congestion based on

packet loss and link utilization history while trying to prevent

non-responsive flows (i.e. flows that do not react to congestion marking

or dropped packets) from impacting performance of responsive flows.

Unlike RED, where the marking probability has to be configured, BLUE

tries to determine the ideal marking probability automatically.

.TP

sfq

Stochastic Fairness Queueing reorders queued traffic so each 'session'

gets to send a packet in turn.

.TP

tbf

The Token Bucket Filter is suited for slowing traffic down to a precisely

configured rate. Scales well to large bandwidths.

.SH CONFIGURING CLASSLESS QDISCS

In the absence of classful qdiscs, classless qdiscs can only be attached at

the root of a device. Full syntax:

.P

.B tc qdisc add dev

\fIDEV\fR

.B root

QDISC QDISC-PARAMETERS

To remove, issue

.P

.B tc qdisc del dev

\fIDEV\fR

.B root

The

.B pfifo_fast

qdisc is the automatic default in the absence of a configured qdisc.

.SH CLASSFUL QDISCS

The classful qdiscs are:

.TP

ATM

Map flows to virtual circuits of an underlying asynchronous transfer mode

device.

.TP

CBQ

Class Based Queueing implements a rich linksharing hierarchy of classes.

It contains shaping elements as well as prioritizing capabilities. Shaping is

performed using link idle time calculations based on average packet size and

underlying link bandwidth. The latter may be ill-defined for some interfaces.

.TP

DRR

The Deficit Round Robin Scheduler is a more flexible replacement for Stochastic

Fairness Queuing. Unlike SFQ, there are no built-in queues \-\- you need to add

classes and then set up filters to classify packets accordingly.  This can be

useful e.g. for using RED qdiscs with different settings for particular

traffic. There is no default class \-\- if a packet cannot be classified, it is

dropped.

.TP

DSMARK

Classify packets based on TOS field, change TOS field of packets based on

classification.

.TP

ETS

The ETS qdisc is a queuing discipline that merges functionality of PRIO and DRR

qdiscs in one scheduler. ETS makes it easy to configure a set of strict and

bandwidth-sharing bands to implement the transmission selection described in

802.1Qaz.

.TP

HFSC

Hierarchical Fair Service Curve guarantees precise bandwidth and delay allocation for leaf classes and allocates excess bandwidth fairly. Unlike HTB, it makes use of packet dropping to achieve low delays which interactive sessions benefit from.

.TP

HTB

The Hierarchy Token Bucket implements a rich linksharing hierarchy of

classes with an emphasis on conforming to existing practices. HTB facilitates

guaranteeing bandwidth to classes, while also allowing specification of upper

limits to inter-class sharing. It contains shaping elements, based on TBF and

can prioritize classes.

.TP

PRIO

The PRIO qdisc is a non-shaping container for a configurable number of

classes which are dequeued in order. This allows for easy prioritization

of traffic, where lower classes are only able to send if higher ones have

no packets available. To facilitate configuration, Type Of Service bits are

honored by default.

.TP

QFQ

Quick Fair Queueing is an O(1) scheduler that provides near-optimal guarantees,

and is the first to achieve that goal with a constant cost also with respect to

the number of groups and the packet length. The QFQ algorithm has no loops, and

uses very simple instructions and data structures that lend themselves very

well to a hardware implementation.

.SH THEORY OF OPERATION

Classes form a tree, where each class has a single parent.

A class may have multiple children. Some qdiscs allow for runtime addition

of classes (CBQ, HTB) while others (PRIO) are created with a static number of

children.

Qdiscs which allow dynamic addition of classes can have zero or more

subclasses to which traffic may be enqueued.

Furthermore, each class contains a

.B leaf qdisc

which by default has

.B pfifo

behaviour, although another qdisc can be attached in place. This qdisc may again

contain classes, but each class can have only one leaf qdisc.

When a packet enters a classful qdisc it can be

.B classified

to one of the classes within. Three criteria are available, although not all

qdiscs will use all three:

.TP

tc filters

If tc filters are attached to a class, they are consulted first

for relevant instructions. Filters can match on all fields of a packet header,

as well as on the firewall mark applied by iptables.

.TP

Type of Service

Some qdiscs have built in rules for classifying packets based on the TOS field.

.TP

skb->priority

Userspace programs can encode a \fIclass-id\fR in the 'skb->priority' field using

the SO_PRIORITY option.

.P

Each node within the tree can have its own filters but higher level filters

may also point directly to lower classes.

If classification did not succeed, packets are enqueued to the leaf qdisc

attached to that class. Check qdisc specific manpages for details, however.

.SH NAMING

All qdiscs, classes and filters have IDs, which can either be specified

or be automatically assigned.

IDs consist of a

.BR major " number and a " minor

number, separated by a colon -

.BR major ":" minor "."

Both

.BR major " and " minor

are hexadecimal numbers and are limited to 16 bits. There are two special

values: root is signified by

.BR major " and " minor

of all ones, and unspecified is all zeros.

.TP

QDISCS

A qdisc, which potentially can have children, gets assigned a

.B major

number, called a 'handle', leaving the

.B minor

number namespace available for classes. The handle is expressed as '10:'.

It is customary to explicitly assign a handle to qdiscs expected to have children.

.TP

CLASSES

Classes residing under a qdisc share their qdisc

.B major

number, but each have a separate

.B minor

number called a 'classid' that has no relation to their

parent classes, only to their parent qdisc. The same naming custom as for

qdiscs applies.

.TP

FILTERS

Filters have a three part ID, which is only needed when using a hashed

filter hierarchy.

.SH PARAMETERS

The following parameters are widely used in TC. For other parameters,

see the man pages for individual qdiscs.

.TP

RATES

Bandwidths or rates.

These parameters accept a floating point number, possibly followed by

either a unit (both SI and IEC units supported), or a float followed by a '%'

character to specify the rate as a percentage of the device's speed

(e.g. 5%, 99.5%). Warning: specifying the rate as a percentage means a fraction

of the current speed; if the speed changes, the value will not be recalculated.

.RS

.TP

bit or a bare number

Bits per second

.TP

kbit

Kilobits per second

.TP

mbit

Megabits per second

.TP

gbit

Gigabits per second

.TP

tbit

Terabits per second

.TP

bps

Bytes per second

.TP

kbps

Kilobytes per second

.TP

mbps

Megabytes per second

.TP

gbps

Gigabytes per second

.TP

tbps

Terabytes per second

.P

To specify in IEC units, replace the SI prefix (k-, m-, g-, t-) with

IEC prefix (ki-, mi-, gi- and ti-) respectively.

.P

TC store rates as a 32-bit unsigned integer in bps internally,

so we can specify a max rate of 4294967295 bps.

.RE

.TP

TIMES

Length of time. Can be specified as a floating point number

followed by an optional unit:

.RS

.TP

s, sec or secs

Whole seconds

.TP

ms, msec or msecs

Milliseconds

.TP

us, usec, usecs or a bare number

Microseconds.

.P

TC defined its own time unit (equal to microsecond) and stores

time values as 32-bit unsigned integer, thus we can specify a max time value

of 4294967295 usecs.

.RE

.TP

SIZES

Amounts of data. Can be specified as a floating point number

followed by an optional unit:

.RS

.TP

b or a bare number

Bytes.

.TP

kbit

Kilobits

.TP

kb or k

Kilobytes

.TP

mbit

Megabits

.TP

mb or m

Megabytes

.TP

gbit

Gigabits

.TP

gb or g

Gigabytes

.P

TC stores sizes internally as 32-bit unsigned integer in byte,

so we can specify a max size of 4294967295 bytes.

.RE

.TP

VALUES

Other values without a unit.

These parameters are interpreted as decimal by default, but you can

indicate TC to interpret them as octal and hexadecimal by adding a '0'

or '0x' prefix respectively.

.SH TC COMMANDS

The following commands are available for qdiscs, classes and filter:

.TP

add

Add a qdisc, class or filter to a node. For all entities, a

.B parent

must be passed, either by passing its ID or by attaching directly to the root of a device.

When creating a qdisc or a filter, it can be named with the

.B handle

parameter. A class is named with the

.B \fBclassid\fR

parameter.

.TP

delete

A qdisc can be deleted by specifying its handle, which may also be 'root'. All subclasses and their leaf qdiscs

are automatically deleted, as well as any filters attached to them.

.TP

change

Some entities can be modified 'in place'. Shares the syntax of 'add', with the exception

that the handle cannot be changed and neither can the parent. In other words,

.B

change

cannot move a node.

.TP

replace

Performs a nearly atomic remove/add on an existing node id. If the node does not exist yet

it is created.

.TP

get

Displays a single filter given the interface \fIDEV\fR, \fIqdisc-id\fR,

\fIpriority\fR, \fIprotocol\fR and \fIfilter-id\fR.

.TP

show

Displays all filters attached to the given interface. A valid parent ID must be passed.

.TP

link

Only available for qdiscs and performs a replace where the node

must exist already.

.SH MONITOR

The\fB\ tc\fR\ utility can monitor events generated by the kernel such as

adding/deleting qdiscs, filters or actions, or modifying existing ones.

The following command is available for\fB\ monitor\fR\ :

.TP

\fBfile\fR

If the file option is given, the \fBtc\fR does not listen to kernel events, but opens

the given file and dumps its contents. The file has to be in binary

format and contain netlink messages.

.SH OPTIONS

.TP

.BR "\-b", " \-b filename", " \-batch", " \-batch filename"

read commands from provided file or standard input and invoke them.

First failure will cause termination of tc.

.TP

.BR "\-force"

don't terminate tc on errors in batch mode.

If there were any errors during execution of the commands, the application return code will be non zero.

.TP

.BR "\-o" , " \-oneline"

output each record on a single line, replacing line feeds

with the

.B '\e'

character. This is convenient when you want to count records

with

.BR wc (1)

or to

.BR grep (1)

the output.

.TP

.BR "\-n" , " \-net" , " \-netns " <NETNS>

switches

.B tc

to the specified network namespace

.IR NETNS .

Actually it just simplifies executing of:

.B ip netns exec

.IR NETNS

.B tc

.RI "[ " OPTIONS " ] " OBJECT " { " COMMAND " | "

.BR help " }"

to

.B tc

.RI "-n[etns] " NETNS " [ " OPTIONS " ] " OBJECT " { " COMMAND " | "

.BR help " }"

.TP

.BR "\-N" , " \-Numeric"

Print the number of protocol, scope, dsfield, etc directly instead of

converting it to human readable name.

.TP

.BR "\-cf" , " \-conf " <FILENAME>

specifies path to the config file. This option is used in conjunction with other options (e.g.

.BR -nm ")."

.TP

.BR "\-t", " \-timestamp"

When\fB\ tc monitor\fR\ runs, print timestamp before the event message in format:

   Timestamp: <Day> <Month> 
 <hh:mm:ss> <YYYY> <usecs> usec

.TP

.BR "\-ts", " \-tshort"

When\fB\ tc monitor\fR\ runs, prints short timestamp before the event message in format:

   [<YYYY>-<MM>-
T<hh:mm:ss>.<ms>]

.SH FORMAT

The show command has additional formatting options:

.TP

.BR "\-s" , " \-stats", " \-statistics"

output more statistics about packet usage.

.TP

.BR "\-d", " \-details"

output more detailed information about rates and cell sizes.

.TP

.BR "\-r", " \-raw"

output raw hex values for handles.

.TP

.BR "\-p", " \-pretty"

for u32 filter, decode offset and mask values to equivalent filter commands based on TCP/IP.

In JSON output, add whitespace to improve readability.

.TP

.BR "\-iec"

print rates in IEC units (ie. 1K = 1024).

.TP

.BR "\-g", " \-graph"

shows classes as ASCII graph. Prints generic stats info under each class if

.BR "-s"

option was specified. Classes can be filtered only by

.BR "dev"

option.

.TP

.BR \-c [ color ][ = { always | auto | never }

Configure color output. If parameter is omitted or

.BR always ,

color output is enabled regardless of stdout state. If parameter is

.BR auto ,

stdout is checked to be a terminal before enabling color output. If parameter is

.BR never ,

color output is disabled. If specified multiple times, the last one takes

precedence. This flag is ignored if

.B \-json

is also given.

.TP

.BR "\-j", " \-json"

Display results in JSON format.

.TP

.BR "\-nm" , " \-name"

resolve class name from

.B /etc/iproute2/tc_cls

file or from file specified by

.B -cf

option. This file is just a mapping of

.B classid

to class name:

.RS 10

# Here is comment

.RE

.RS 10

1:40   voip # Here is another comment

.RE

.RS 10

1:50   web

.RE

.RS 10

1:60   ftp

.RE

.RS 10

1:2    home

.RE

.RS

.B tc

will not fail if

.B -nm

was specified without

.B -cf

option but

.B /etc/iproute2/tc_cls

file does not exist, which makes it possible to pass

.B -nm

option for creating

.B tc

alias.

.RE

.SH "EXAMPLES"

.PP

tc -g class show dev eth0

.RS 4

Shows classes as ASCII graph on eth0 interface.

.RE

.PP

tc -g -s class show dev eth0

.RS 4

Shows classes as ASCII graph with stats info under each class.

.RE

.SH HISTORY

.B tc

was written by Alexey N. Kuznetsov and added in Linux 2.2.

.SH SEE ALSO

.BR tc-basic (8),

.BR tc-bfifo (8),

.BR tc-bpf (8),

.BR tc-cake (8),

.BR tc-cbq (8),

.BR tc-cgroup (8),

.BR tc-choke (8),