# This file is part of systemd. # # systemd is free software; you can redistribute it and/or modify it # under the terms of the GNU Lesser General Public License as published by # the Free Software Foundation; either version 2.1 of the License, or # (at your option) any later version. # See sysctl.d(5) and core(5) for documentation. # To override settings in this file, create a local file in /etc # (e.g. /etc/sysctl.d/90-override.conf), and put any assignments # there. # System Request functionality of the kernel (SYNC) # # Use kernel.sysrq = 1 to allow all keys. # See https://www.kernel.org/doc/html/latest/admin-guide/sysrq.html for a list # of values and keys. #kernel.sysrq = 16 # Ubuntu uses /etc/sysctl.d/10-magic-sysrq.conf # Append the PID to the core filename kernel.core_uses_pid = 1 # Source route verification net.ipv4.conf.default.rp_filter = 2 net.ipv4.conf.*.rp_filter = 2 #-net.ipv4.conf.all.rp_filter # Ubuntu uses /etc/sysctl.d/10-network-security.conf # Do not accept source routing net.ipv4.conf.default.accept_source_route = 0 net.ipv4.conf.*.accept_source_route = 0 -net.ipv4.conf.all.accept_source_route # Promote secondary addresses when the primary address is removed net.ipv4.conf.default.promote_secondaries = 1 net.ipv4.conf.*.promote_secondaries = 1 -net.ipv4.conf.all.promote_secondaries # ping(8) without CAP_NET_ADMIN and CAP_NET_RAW # The upper limit is set to 2^31-1. Values greater than that get rejected by # the kernel because of this definition in linux/include/net/ping.h: # #define GID_T_MAX (((gid_t)~0U) >> 1) # That's not so bad because values between 2^31 and 2^32-1 are reserved on # systemd-based systems anyway: https://systemd.io/UIDS-GIDS#summary -net.ipv4.ping_group_range = 0 2147483647 # Fair Queue CoDel packet scheduler to fight bufferbloat -net.core.default_qdisc = fq_codel # Enable hard and soft link protection fs.protected_hardlinks = 1 fs.protected_symlinks = 1 # Enable regular file and FIFO protection fs.protected_regular = 1 fs.protected_fifos = 1