.SH NAME
tc \- show / manipulate traffic control settings
.SH SYNOPSIS
-.B tc qdisc [ add | change | replace | link | delete ] dev
-DEV
+.B tc
+.RI "[ " OPTIONS " ]"
+.B qdisc [ add | change | replace | link | delete ] dev
+\fIDEV\fR
.B
[ parent
-qdisc-id
+\fIqdisc-id\fR
.B | root ]
.B [ handle
-qdisc-id ] qdisc
+\fIqdisc-id\fR ]
+.B [ ingress_block
+\fIBLOCK_INDEX\fR ]
+.B [ egress_block
+\fIBLOCK_INDEX\fR ] qdisc
[ qdisc specific parameters ]
.P
-.B tc class [ add | change | replace | delete ] dev
-DEV
+.B tc
+.RI "[ " OPTIONS " ]"
+.B class [ add | change | replace | delete ] dev
+\fIDEV\fR
.B parent
-qdisc-id
+\fIqdisc-id\fR
.B [ classid
-class-id ] qdisc
+\fIclass-id\fR ] qdisc
[ qdisc specific parameters ]
.P
-.B tc filter [ add | change | replace | delete ] dev
-DEV
+.B tc
+.RI "[ " OPTIONS " ]"
+.B filter [ add | change | replace | delete | get ] dev
+\fIDEV\fR
.B [ parent
-qdisc-id
-.B | root ] protocol
-protocol
+\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
-priority filtertype
+\fIpriority\fR filtertype
[ filtertype specific parameters ]
.B flowid
-flow-id
+\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 [ dev
-DEV
+\fIDEV\fR
.B ]
.P
.B tc
+.RI "[ " OPTIONS " ]"
.RI "[ " FORMAT " ]"
.B class show dev
-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 filter show dev
-DEV
+.B tc
+.RI "[ " OPTIONS " ]"
+.B chain show block
+\fIBLOCK_INDEX\fR
.P
-.B tc [ -force ] -b\fR[\fIatch\fR] \fB[ filename ]
+.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\-i\fR[\fIec\fR] }
+\fB\-col\fR[\fIor\fR] }
.SH DESCRIPTION
.B Tc
.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 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
+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.
the root of a device. Full syntax:
.P
.B tc qdisc add dev
-DEV
+\fIDEV\fR
.B root
QDISC QDISC-PARAMETERS
To remove, issue
.P
.B tc qdisc del dev
-DEV
+\fIDEV\fR
.B root
The
.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
+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
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
Some qdiscs have built in rules for classifying packets based on the TOS field.
.TP
skb->priority
-Userspace programs can encode a class-id in the 'skb->priority' field using
+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
All qdiscs, classes and filters have IDs, which can either be specified
or be automatically assigned.
-IDs consist of a major number and a minor number, separated by a colon.
-Both major and minor number are limited to 16 bits. There are two special
-values: root is signified by major and minor of all ones, and unspecified
-is all zeros.
+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 major number, called a 'handle', leaving the minor
+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.
+It is customary to explicitly assign a handle to qdiscs expected to have children.
.TP
CLASSES
-Classes residing under a qdisc share their qdisc major number, but each have
-a separate minor number called a 'classid' that has no relation to their
+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.
RATES
Bandwidths or rates.
These parameters accept a floating point number, possibly followed by
-a unit (both SI and IEC units supported).
+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
When creating a qdisc or a filter, it can be named with the
.B handle
parameter. A class is named with the
-.B classid
+.B \fBclassid\fR
parameter.
.TP
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> <DD> <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>-<DD>T<hh:mm:ss>.<ms>]
+
.SH FORMAT
The show command has additional formatting options:
.TP
.BR "\-p", " \-pretty"
-decode filter offset and mask values to equivalent filter commands based on TCP/IP.
+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 "\-b", " \-b filename", " \-batch", " \-batch filename"
-read commands from provided file or standard input and invoke them.
-First failure will cause termination of tc.
+.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 "\-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.
+.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.
.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),
.BR tc-codel (8),
.BR tc-drr (8),
.BR tc-ematch (8),
+.BR tc-flow (8),
+.BR tc-flower (8),
+.BR tc-fq (8),
.BR tc-fq_codel (8),
+.BR tc-fw (8),
.BR tc-hfsc (7),
.BR tc-hfsc (8),
.BR tc-htb (8),
.BR tc-mqprio (8),
.BR tc-pfifo (8),
.BR tc-pfifo_fast (8),
+.BR tc-pie (8),
.BR tc-red (8),
+.BR tc-route (8),
.BR tc-sfb (8),
.BR tc-sfq (8),
.BR tc-stab (8),
.BR tc-tbf (8),
+.BR tc-tcindex (8),
+.BR tc-u32 (8),
.br
.RB "User documentation at " http://lartc.org/ ", but please direct bugreports and patches to: " <netdev@vger.kernel.org>
.SH AUTHOR
Manpage maintained by bert hubert (ahu@ds9a.nl)
-
projects / mirror_iproute2.git / blobdiff