SYSCTL(8)                 (2020-02-27)                  SYSCTL(8)

     NAME
          sysctl - configure kernel parameters at runtime

     SYNOPSIS
          sysctl [options] [variable[=value]] [...]
          sysctl -p [file or regexp] [...]

     DESCRIPTION
          sysctl is used to modify kernel parameters at runtime.  The
          parameters available are those listed under /proc/sys/.
          Procfs is required for sysctl support in Linux.  You can use
          sysctl to both read and write sysctl data.

     PARAMETERS
          variable
               The name of a key to read from.  An example is
               kernel.ostype.  The '/' separator is also accepted in
               place of a '.'.

          value
               To set a key, use the form variable=value where
               variable is the key and value is the value to set it
               to.  If the value contains quotes or characters which
               are parsed by the shell, you may need to enclose the
               value in double quotes.

          -n, --values
               Use this option to disable printing of the key name
               when printing values.

          -e, --ignore
               Use this option to ignore errors about unknown keys.

          -N, --names
               Use this option to only print the names.  It may be
               useful with shells that have programmable completion.

          -q, --quiet
               Use this option to not display the values set to std-
               out.

          -w, --write
               Use this option when all arguments prescribe a key to
               be set.

          -p[FILE], --load[=FILE]
               Load in sysctl settings from the file specified or
               /etc/sysctl.conf if none given.  Specifying - as file-
               name means reading data from standard input.  Using
               this option will mean arguments to sysctl are files,

     Page 1                      procps-ng           (printed 5/24/22)

     SYSCTL(8)                 (2020-02-27)                  SYSCTL(8)

               which are read in the order they are specified.  The
               file argument may be specified as regular expression.

          -a, --all
               Display all values currently available.

          --deprecated
               Include deprecated parameters to --all values listing.

          -b, --binary
               Print value without new line.

          --system
               Load settings from all system configuration files.
               Files are read from directories in the following list
               in given order from top to bottom.  Once a file of a
               given filename is loaded, any file of the same name in
               subsequent directories is ignored.
               /etc/sysctl.d/*.conf
               /run/sysctl.d/*.conf
               /usr/local/lib/sysctl.d/*.conf
               /usr/lib/sysctl.d/*.conf
               /lib/sysctl.d/*.conf
               /etc/sysctl.conf

          -r, --pattern pattern
               Only apply settings that match pattern. The pattern
               uses extended regular expression syntax.

          -A   Alias of -a

          -d   Alias of -h

          -f   Alias of -p

          -X   Alias of -a

          -o   Does nothing, exists for BSD compatibility.

          -x   Does nothing, exists for BSD compatibility.

          -h, --help
               Display help text and exit.

          -V, --version
               Display version information and exit.

     EXAMPLES
          /sbin/sysctl -a
          /sbin/sysctl -n kernel.hostname
          /sbin/sysctl -w kernel.domainname="example.com"
          /sbin/sysctl -p/etc/sysctl.conf

     Page 2                      procps-ng           (printed 5/24/22)

     SYSCTL(8)                 (2020-02-27)                  SYSCTL(8)

          /sbin/sysctl -a --pattern forward
          /sbin/sysctl -a --pattern forward$
          /sbin/sysctl -a --pattern 'net.ipv4.conf.(eth|wlan)0.arp'
          /sbin/sysctl --system --pattern '^net.ipv6'

     DEPRECATED PARAMETERS
          The base_reachable_time and retrans_time are deprecated.
          The sysctl command does not allow changing values of these
          parameters.  Users who insist to use deprecated kernel
          interfaces should push values to /proc file system by other
          means.  For example:

          echo 256 > /proc/sys/net/ipv6/neigh/eth0/base_reachable_time

     FILES
          /proc/sys
          /etc/sysctl.d/*.conf
          /run/sysctl.d/*.conf
          /usr/local/lib/sysctl.d/*.conf
          /usr/lib/sysctl.d/*.conf
          /lib/sysctl.d/*.conf
          /etc/sysctl.conf

     SEE ALSO
          sysctl.conf(5) regex(7)

     AUTHOR
          George Staikos

     REPORTING BUGS
          Please send bug reports to

     Page 3                      procps-ng           (printed 5/24/22)