sysctl.d/50-default.conf

   1 #  This file is part of systemd.
   2 #
   3 #  systemd is free software; you can redistribute it and/or modify it
   4 #  under the terms of the GNU Lesser General Public License as published by
   5 #  the Free Software Foundation; either version 2.1 of the License, or
   6 #  (at your option) any later version.
   7
   8 # See sysctl.d(5) and core(5) for documentation.
   9
  10 # To override settings in this file, create a local file in /etc
  11 # (e.g. /etc/sysctl.d/90-override.conf), and put any assignments
  12 # there.
  13
  14 # System Request functionality of the kernel (SYNC)
  15 #
  16 # Use kernel.sysrq = 1 to allow all keys.
  17 # See https://www.kernel.org/doc/html/latest/admin-guide/sysrq.html for a list
  18 # of values and keys.
  19 kernel.sysrq = 16
  20
  21 # Append the PID to the core filename
  22 kernel.core_uses_pid = 1
  23
  24 # Source route verification
  25 net.ipv4.conf.default.rp_filter = 2
  26 net.ipv4.conf.*.rp_filter = 2
  27 -net.ipv4.conf.all.rp_filter
  28
  29 # Do not accept source routing
  30 net.ipv4.conf.default.accept_source_route = 0
  31 net.ipv4.conf.*.accept_source_route = 0
  32 -net.ipv4.conf.all.accept_source_route
  33
  34 # Promote secondary addresses when the primary address is removed
  35 net.ipv4.conf.default.promote_secondaries = 1
  36 net.ipv4.conf.*.promote_secondaries = 1
  37 -net.ipv4.conf.all.promote_secondaries
  38
  39 # ping(8) without CAP_NET_ADMIN and CAP_NET_RAW
  40 # The upper limit is set to 2^31-1. Values greater than that get rejected by
  41 # the kernel because of this definition in linux/include/net/ping.h:
  42 #   #define GID_T_MAX (((gid_t)~0U) >> 1)
  43 # That's not so bad because values between 2^31 and 2^32-1 are reserved on
  44 # systemd-based systems anyway: https://systemd.io/UIDS-GIDS.html#summary
  45 -net.ipv4.ping_group_range = 0 2147483647
  46
  47 # Fair Queue CoDel packet scheduler to fight bufferbloat
  48 net.core.default_qdisc = fq_codel
  49
  50 # Enable hard and soft link protection
  51 fs.protected_hardlinks = 1
  52 fs.protected_symlinks = 1
  53
  54 # Enable regular file and FIFO protection
  55 fs.protected_regular = 1
  56 fs.protected_fifos = 1