tc-gate(8) — Linux manual page

NAME \| SYNOPSIS \| DESCRIPTION \| PARAMETERS \| EXAMPLES \| AUTHORS \| COLOPHON

GATE(8)                           Linux                           GATE(8)

NAME top

       gate - Stream Gate Action

SYNOPSIS top

       tc  ...  action gate
               [ base-time BASETIME ] [ clockid CLOCKID ]
               sched-entry <gate state> <interval 1> [ <internal
       priority> <max octets> ]
               sched-entry <gate state> <interval 2> [ <internal
       priority> <max octets> ]
               sched-entry <gate state> <interval 3> [ <internal
       priority> <max octets> ]
               ......
               sched-entry <gate state> <interval N> [ <internal
       priority> <max octets> ]

DESCRIPTION top

       GATE action allows specified ingress frames can be passed at
       specific time slot, or be dropped at specific time slot. Tc filter
       filters the ingress frames, then tc gate action would specify
       which time slot and how many bytes these frames can be passed to
       device and which time slot frames would be dropped.  Gate action
       also assign a base-time to tell when the entry list start.  Then
       gate action would start to repeat the gate entry list cyclically
       at the start base-time.  For the software simulation, gate action
       requires the user assign reference time clock type.

PARAMETERS top

       base-time
              Specifies the instant in nanoseconds, defining the time
              when the schedule starts. If 'base-time' is a time in the
              past, the schedule will start at

              base-time + (N * cycle-time)

              where N is the smallest integer so the resulting time is
              greater than "now", and "cycle-time" is the sum of all the
              intervals of the entries in the schedule. Without base-time
              specified, will default to be 0.

       clockid
              Specifies the clock to be used by qdisc's internal timer
              for measuring time and scheduling events. Not valid if gate
              action is used for offloading filter.  For example, tc
              filter command with skip_sw parameter.

       sched-entry
              There may multiple sched-entry parameters in a single
              schedule. Each one has the format:

              sched-entry <gate state> <interval> [ <internal priority>
              <max octets> ]

              <gate state> means gate states. 'open' keep gate open,
              'close' keep gate close.
              <interval> means how much nano seconds for this time slot.
              <internal priority> means internal priority value. Present
              of the internal receiving queue for this stream. "-1" means
              wildcard.  <internal priority> and <max octets> can be omit
              default to be "-1" which both
               value to be "-1" for this <sched-entry>.
              <max octets> means how many octets size could pass in this
              time slot. Dropped if overlimited. "-1" means wildcard.
              <max octets> can be omit default to be "-1" which value to
              be "-1" for this <sched-entry>.
              Note that <internal priority> and <max octets> are nothing
              meaning for gate state is "close" in a "sched-entry". All
              frames are dropped when "sched-entry" with "close" state.

EXAMPLES top

       The following example shows tc filter frames source ip match to
       the 192.168.0.20 will keep the gate open for 200ms and limit the
       traffic to 8MB in this sched-entry. Then keep the traffic gate to
       be close for 100ms.  Frames arrived at gate close state would be
       dropped. Then the cycle would run the gate entries periodically.
       The schedule will start at instant 200.0s using the reference
       CLOCK_TAI. The schedule is composed of two entries each of 300ms
       duration.

       # tc qdisc add dev eth0 ingress
       # tc filter add dev eth0 parent ffff: protocol ip \
                  flower skip_hw src_ip 192.168.0.20 \
                  action gate index 2 clockid CLOCK_TAI \
                  base-time 200000000000ns \
                  sched-entry open 200000000ns -1 8000000b \
                  sched-entry close 100000000ns

       Following commands is an example to filter a stream source mac
       match to the 10:00:80:00:00:00 icmp frames will be dropped at any
       time with cycle 200ms.  With a default basetime 0 and clockid is
       CLOCK_TAI as default.

       # tc qdisc add dev eth0 ingress
       # tc filter add dev eth0 parent ffff:  protocol ip \
            flower ip_proto icmp dst_mac 10:00:80:00:00:00 \
            action gate index 12 sched-entry close 200000000ns

AUTHORS top

       Po Liu <[email protected]>

COLOPHON top

       This page is part of the iproute2 (utilities for controlling
       TCP/IP networking and traffic) project.  Information about the
       project can be found at 
       ⟨http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2⟩.
       If you have a bug report for this manual page, send it to
       [email protected], [email protected].  This page was
       obtained from the project's upstream Git repository
       ⟨https://git.kernel.org/pub/scm/network/iproute2/iproute2.git⟩ on
       2025-08-11.  (At that time, the date of the most recent commit
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       COLOPHON (which is not part of the original manual page), send a
       mail to [email protected]

iproute2                       12 Mar 2020                        GATE(8)