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. 19kernel.sysrq = 16 20 21# Append the PID to the core filename 22kernel.core_uses_pid = 1 23 24# Source route verification 25net.ipv4.conf.default.rp_filter = 2 26net.ipv4.conf.*.rp_filter = 2 27-net.ipv4.conf.all.rp_filter 28 29# Do not accept source routing 30net.ipv4.conf.default.accept_source_route = 0 31net.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 35net.ipv4.conf.default.promote_secondaries = 1 36net.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#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 51fs.protected_hardlinks = 1 52fs.protected_symlinks = 1 53 54# Enable regular file and FIFO protection 55fs.protected_regular = 1 56fs.protected_fifos = 1 57